Internals Bugfixes & Internals-Compatible Helmets (#70750)

* Core internals refactor. Add open/close_internals procs to /obj/item/tank. Add open/close_internals, can_breathe_internals, and invalid_internals procs to /mob/living/carbon. Fixed bug in human_stripping.dm preventing changing internals for breathing tube users. Fixed bug in /obj/item/tank/toggle_internals that was auto-adjusting non-internals masks. Fixed bug in slements/strippable that caused two mobs to breathe from the same internals.

code/__DEFINES/obj_flags.dm

@@ -65,6 +65,8 @@
 #define CASTING_CLOTHES (1<<19)
 ///Moths can't eat the clothing that has this flag.
 #define INEDIBLE_CLOTHING (1<<20)
+/// Headgear/helmet allows internals
+#define HEADINTERNALS (1<<21)
 
 /// Integrity defines for clothing (not flags but close enough)
 #define CLOTHING_PRISTINE 0 // We have no damage on the clothing

code/datums/outfit.dm

@@ -245,8 +245,7 @@
 	if(!visualsOnly)
 		apply_fingerprints(H)
 		if(internals_slot)
-			H.internal = H.get_item_by_slot(internals_slot)
-			H.update_action_buttons_icon()
+			H.open_internals(H.get_item_by_slot(internals_slot))
 		if(implants)
 			for(var/implant_type in implants)
 				var/obj/item/implant/I = SSwardrobe.provide_type(implant_type, H)

code/game/objects/items/tanks/tank_types.dm

@@ -8,6 +8,16 @@
  * Generic
  */
 
+/// Allows carbon to toggle internals via AltClick of the equipped tank.
+/obj/item/tank/internals/AltClick(mob/user)
+	..()
+	if((loc == user) && user.canUseTopic(src, be_close = TRUE, no_dexterity = FALSE, no_tk = TRUE, need_hands = TRUE))
+		toggle_internals(user)
+
+/obj/item/tank/internals/examine(mob/user)
+	. = ..()
+	. += span_notice("Alt-click the tank to toggle the valve.")
+
 /*
  * Oxygen
  */

code/game/objects/items/tanks/tanks.dm

@@ -44,38 +44,42 @@
 	var/list/explosion_info
 	/// List containing reactions happening inside our tank.
 	var/list/reaction_info
+	/// Mob that is currently breathing from the tank.
+	var/mob/living/carbon/breathing_mob = null
+
+/// Closes the tank if dropped while open.
+/obj/item/tank/dropped(mob/living/user, silent)
+	. = ..()
+	// Close open air tank if its current user got sent to the shadowrealm.
+	if (QDELETED(breathing_mob))
+		breathing_mob = null
+		return
+	// Close open air tank if it got dropped by it's current user.
+	if (loc != breathing_mob)
+		breathing_mob.cutoff_internals()
+
+/// Closes the tank if given to another mob while open.
+/obj/item/tank/equipped(mob/living/user, slot, initial)
+	. = ..()
+	// Close open air tank if it was equipped by a mob other than the current user.
+	if (breathing_mob && (user != breathing_mob))
+		breathing_mob.cutoff_internals()
+
+/// Called by carbons after they connect the tank to their breathing apparatus.
+/obj/item/tank/proc/after_internals_opened(mob/living/carbon/carbon_target)
+	breathing_mob = carbon_target
+
+/// Called by carbons after they disconnect the tank from their breathing apparatus.
+/obj/item/tank/proc/after_internals_closed(mob/living/carbon/carbon_target)
+	breathing_mob = null
+
+/// Attempts to toggle the mob's internals on or off using this tank. Returns TRUE if successful.
+/obj/item/tank/proc/toggle_internals(mob/living/carbon/mob_target)
+	return mob_target.toggle_internals(src)
 
 /obj/item/tank/ui_action_click(mob/user)
 	toggle_internals(user)
 
-/obj/item/tank/proc/toggle_internals(mob/user)
-	var/mob/living/carbon/human/H = user
-	if(!istype(H))
-		return
-
-	if(H.internal == src)
-		to_chat(H, span_notice("You close [src] valve."))
-		H.internal = null
-	else
-		if(!H.getorganslot(ORGAN_SLOT_BREATHING_TUBE))
-			if(!H.wear_mask)
-				to_chat(H, span_warning("You need a mask!"))
-				return
-			var/is_clothing = isclothing(H.wear_mask)
-			if(is_clothing && H.wear_mask.mask_adjusted)
-				H.wear_mask.adjustmask(H)
-			if(!is_clothing || !(H.wear_mask.clothing_flags & MASKINTERNALS))
-				to_chat(H, span_warning("[H.wear_mask] can't use [src]!"))
-				return
-
-		if(H.internal)
-			to_chat(H, span_notice("You switch your internals to [src]."))
-		else
-			to_chat(H, span_notice("You open [src] valve."))
-		H.internal = src
-	H.update_action_buttons_icon()
-
-
 /obj/item/tank/Initialize(mapload)
 	. = ..()
 
@@ -110,8 +114,8 @@
 /obj/item/tank/examine(mob/user)
 	var/obj/icon = src
 	. = ..()
-	if(istype(src.loc, /obj/item/assembly))
-		icon = src.loc
+	if(istype(loc, /obj/item/assembly))
+		icon = loc
 	if(!in_range(src, user) && !isobserver(user))
 		if(icon == src)
 			. += span_notice("If you want any more information you'll need to get closer.")
@@ -145,21 +149,21 @@
 	return ..()
 
 /obj/item/tank/suicide_act(mob/user)
-	var/mob/living/carbon/human/H = user
+	var/mob/living/carbon/human/human_user = user
 	user.visible_message(span_suicide("[user] is putting [src]'s valve to [user.p_their()] lips! It looks like [user.p_theyre()] trying to commit suicide!"))
 	playsound(loc, 'sound/effects/spray.ogg', 10, TRUE, -3)
-	if(!QDELETED(H) && air_contents && air_contents.return_pressure() >= 1000)
-		ADD_TRAIT(H, TRAIT_DISFIGURED, TRAIT_GENERIC)
-		H.inflate_gib()
+	if(!QDELETED(human_user) && air_contents && air_contents.return_pressure() >= 1000)
+		ADD_TRAIT(human_user, TRAIT_DISFIGURED, TRAIT_GENERIC)
+		human_user.inflate_gib()
 		return MANUAL_SUICIDE
 	else
 		to_chat(user, span_warning("There isn't enough pressure in [src] to commit suicide with..."))
 	return SHAME
 
-/obj/item/tank/attackby(obj/item/W, mob/user, params)
+/obj/item/tank/attackby(obj/item/attacking_item, mob/user, params)
 	add_fingerprint(user)
-	if(istype(W, /obj/item/assembly_holder))
-		bomb_assemble(W, user)
+	if(istype(attacking_item, /obj/item/assembly_holder))
+		bomb_assemble(attacking_item, user)
 		return TRUE
 	return ..()
 
@@ -187,10 +191,10 @@
 		"releasePressure" = round(distribute_pressure)
 	)
 
-	var/mob/living/carbon/C = user
-	if(!istype(C))
-		C = loc.loc
-	if(istype(C) && C.internal == src)
+	var/mob/living/carbon/carbon_user = user
+	if(!istype(carbon_user))
+		carbon_user = loc
+	if(istype(carbon_user) && (carbon_user.external == src || carbon_user.internal == src))
 		.["connected"] = TRUE
 
 /obj/item/tank/ui_act(action, params)

code/modules/antagonists/changeling/powers/mutations.dm

@@ -507,7 +507,7 @@
 	inhand_icon_state = null
 	desc = "A covering of pressure and temperature-resistant organic tissue with a glass-like chitin front."
 	item_flags = DROPDEL
-	clothing_flags = STOPSPRESSUREDAMAGE
+	clothing_flags = STOPSPRESSUREDAMAGE | HEADINTERNALS
 	armor = list(MELEE = 0, BULLET = 0, LASER = 0,ENERGY = 0, BOMB = 0, BIO = 100, FIRE = 90, ACID = 90)
 	flags_cover = HEADCOVERSEYES | HEADCOVERSMOUTH
 

code/modules/antagonists/cult/cult_items.dm

@@ -266,7 +266,7 @@ Striking a noncultist, however, will tear their flesh."}
 	icon_state = "cult_helmet"
 	inhand_icon_state = null
 	armor = list(MELEE = 50, BULLET = 40, LASER = 50, ENERGY = 60, BOMB = 50, BIO = 100, FIRE = 100, ACID = 100)
-	clothing_flags = STOPSPRESSUREDAMAGE | THICKMATERIAL | SNUG_FIT | PLASMAMAN_HELMET_EXEMPT
+	clothing_flags = STOPSPRESSUREDAMAGE | THICKMATERIAL | SNUG_FIT | PLASMAMAN_HELMET_EXEMPT | HEADINTERNALS
 	flags_inv = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDEFACIALHAIR|HIDESNOUT
 	min_cold_protection_temperature = SPACE_HELM_MIN_TEMP_PROTECT
 	max_heat_protection_temperature = SPACE_HELM_MAX_TEMP_PROTECT

code/modules/antagonists/ert/ert.dm

@@ -232,7 +232,7 @@
 		return
 	if(isplasmaman(H))
 		H.equipOutfit(plasmaman_outfit)
-		H.internal = H.get_item_for_held_index(2)
+		H.open_internals(H.get_item_for_held_index(2))
 	H.equipOutfit(outfit)
 
 

code/modules/clothing/head/hardhat.dm

@@ -102,7 +102,7 @@
 	dog_fashion = null
 	name = "atmospheric technician's firefighting helmet"
 	desc = "A firefighter's helmet, able to keep the user cool in any situation."
-	clothing_flags = STOPSPRESSUREDAMAGE | THICKMATERIAL | BLOCK_GAS_SMOKE_EFFECT | PLASMAMAN_HELMET_EXEMPT
+	clothing_flags = STOPSPRESSUREDAMAGE | THICKMATERIAL | BLOCK_GAS_SMOKE_EFFECT | PLASMAMAN_HELMET_EXEMPT | HEADINTERNALS
 	flags_inv = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDEFACIALHAIR|HIDESNOUT
 	heat_protection = HEAD
 	max_heat_protection_temperature = FIRE_IMMUNITY_MAX_TEMP_PROTECT

code/modules/clothing/masks/_masks.dm

@@ -62,12 +62,12 @@
 		M.update_worn_mask()
 
 //Proc that moves gas/breath masks out of the way, disabling them and allowing pill/food consumption
-/obj/item/clothing/mask/proc/adjustmask(mob/living/user)
+/obj/item/clothing/mask/proc/adjustmask(mob/living/carbon/user)
 	if(user?.incapacitated())
 		return
 	mask_adjusted = !mask_adjusted
 	if(!mask_adjusted)
-		src.icon_state = initial(icon_state)
+		icon_state = initial(icon_state)
 		clothing_flags |= visor_flags
 		flags_inv |= visor_flags_inv
 		flags_cover |= visor_flags_cover
@@ -81,9 +81,14 @@
 		flags_cover &= ~visor_flags_cover
 		if(adjusted_flags)
 			slot_flags = adjusted_flags
-	if(user)
+	if(!istype(user))
+		return
+	// Update the mob if it's wearing the mask.
+	if(user.wear_mask == src)
 		user.wear_mask_update(src, toggle_off = mask_adjusted)
-		user.update_action_buttons_icon() //when mask is adjusted out, we update all buttons icon so the user's potential internal tank correctly shows as off.
+	if(loc == user)
+		// Update action button icon for adjusted mask, if someone is holding it.
+		user.update_action_buttons_icon()
 
 /**
  * Proc called in lungs.dm to act if wearing a mask with filters, used to reduce the filters durability, return a changed gas mixture depending on the filter status

code/modules/clothing/masks/breath.dm

@@ -22,7 +22,7 @@
 
 /obj/item/clothing/mask/breath/AltClick(mob/user)
 	..()
-	if(!user.canUseTopic(src, be_close = TRUE, no_dexterity = TRUE, no_tk = FALSE, need_hands = !iscyborg(user)))
+	if(user.canUseTopic(src, be_close = TRUE, no_dexterity = TRUE, no_tk = FALSE, need_hands = !iscyborg(user)))
 		adjustmask(user)
 
 /obj/item/clothing/mask/breath/examine(mob/user)

code/modules/clothing/spacesuits/_spacesuits.dm

@@ -9,7 +9,7 @@
 	icon_state = "spaceold"
 	inhand_icon_state = "space_helmet"
 	desc = "A special helmet with solar UV shielding to protect your eyes from harmful rays."
-	clothing_flags = STOPSPRESSUREDAMAGE | THICKMATERIAL | SNUG_FIT | PLASMAMAN_HELMET_EXEMPT
+	clothing_flags = STOPSPRESSUREDAMAGE | THICKMATERIAL | SNUG_FIT | PLASMAMAN_HELMET_EXEMPT | HEADINTERNALS
 	armor = list(MELEE = 0, BULLET = 0, LASER = 0,ENERGY = 0, BOMB = 0, BIO = 100, FIRE = 80, ACID = 70)
 	flags_inv = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDEFACIALHAIR|HIDESNOUT
 

code/modules/clothing/suits/bio.dm

@@ -6,7 +6,7 @@
 	worn_icon = 'icons/mob/clothing/head/bio.dmi'
 	icon_state = "bio"
 	inhand_icon_state = "bio_hood"
-	clothing_flags = THICKMATERIAL | BLOCK_GAS_SMOKE_EFFECT | SNUG_FIT | PLASMAMAN_HELMET_EXEMPT
+	clothing_flags = THICKMATERIAL | BLOCK_GAS_SMOKE_EFFECT | SNUG_FIT | PLASMAMAN_HELMET_EXEMPT | HEADINTERNALS
 	armor = list(MELEE = 0, BULLET = 0, LASER = 0,ENERGY = 0, BOMB = 0, BIO = 100, FIRE = 30, ACID = 100)
 	flags_inv = HIDEMASK|HIDEEARS|HIDEEYES|HIDEHAIR|HIDEFACIALHAIR|HIDEFACE|HIDESNOUT
 	resistance_flags = ACID_PROOF

code/modules/mob/living/carbon/carbon_defines.dm

@@ -36,7 +36,10 @@
 	var/obj/item/back = null
 	var/obj/item/clothing/mask/wear_mask = null
 	var/obj/item/clothing/neck/wear_neck = null
+	/// Equipped air tank. Never set this manually.
 	var/obj/item/tank/internal = null
+	/// "External" air tank. Never set this manually. Not required to stay directly equipped on the mob (i.e. could be a machine or MOD suit module).
+	var/obj/item/tank/external = null
 	var/obj/item/clothing/head = null
 
 	///only used by humans

code/modules/mob/living/carbon/human/human.dm

@@ -81,15 +81,13 @@
 
 /mob/living/carbon/human/get_status_tab_items()
 	. = ..()
-	if (internal)
-		var/datum/gas_mixture/internal_air = internal.return_air()
-		if (!internal_air)
-			QDEL_NULL(internal)
-		else
-			. += ""
-			. += "Internal Atmosphere Info: [internal.name]"
-			. += "Tank Pressure: [internal_air.return_pressure()]"
-			. += "Distribution Pressure: [internal.distribute_pressure]"
+	var/obj/item/tank/target_tank = internal || external
+	if(target_tank)
+		var/datum/gas_mixture/internal_air = target_tank.return_air()
+		. += ""
+		. += "Internal Atmosphere Info: [target_tank.name]"
+		. += "Tank Pressure: [internal_air.return_pressure()]"
+		. += "Distribution Pressure: [target_tank.distribute_pressure]"
 	if(istype(wear_suit, /obj/item/clothing/suit/space))
 		var/obj/item/clothing/suit/space/S = wear_suit
 		. += "Thermal Regulator: [S.thermal_on ? "on" : "off"]"

code/modules/mob/living/carbon/human/human_stripping.dm

@@ -185,13 +185,11 @@ GLOBAL_LIST_INIT(strippable_human_items, create_strippable_list(list(
 		return
 
 	var/mob/living/carbon/carbon_source = source
-
-	var/obj/item/clothing/mask = carbon_source.wear_mask
-	if (!istype(mask))
-		return
-
-	if ((mask.clothing_flags & MASKINTERNALS) && istype(item, /obj/item/tank))
-		return isnull(carbon_source.internal) ? "enable_internals" : "disable_internals"
+	if (carbon_source.can_breathe_internals() && istype(item, /obj/item/tank))
+		if(carbon_source.internal != item)
+			return "enable_internals"
+		else
+			return "disable_internals"
 
 /proc/strippable_alternate_action_internals(obj/item/item, atom/source, mob/user)
 	var/obj/item/tank/tank = item
@@ -202,28 +200,26 @@ GLOBAL_LIST_INIT(strippable_human_items, create_strippable_list(list(
 	if (!istype(carbon_source))
 		return
 
-	var/obj/item/clothing/mask = carbon_source.wear_mask
-	if (!istype(mask) || !(mask.clothing_flags & MASKINTERNALS))
+	if (!carbon_source.can_breathe_internals())
 		return
 
 	carbon_source.visible_message(
-		span_danger("[user] tries to [isnull(carbon_source.internal) ? "open": "close"] the valve on [source]'s [item.name]."),
-		span_userdanger("[user] tries to [isnull(carbon_source.internal) ? "open": "close"] the valve on your [item.name]."),
+		span_danger("[user] tries to [(carbon_source.internal != item) ? "open" : "close"] the valve on [source]'s [item.name]."),
+		span_userdanger("[user] tries to [(carbon_source.internal != item) ? "open" : "close"] the valve on your [item.name]."),
 		ignored_mobs = user,
 	)
 
-	to_chat(user, span_notice("You try to [isnull(carbon_source.internal) ? "open": "close"] the valve on [source]'s [item.name]..."))
+	to_chat(user, span_notice("You try to [(carbon_source.internal != item) ? "open" : "close"] the valve on [source]'s [item.name]..."))
 
 	if(!do_mob(user, carbon_source, INTERNALS_TOGGLE_DELAY))
 		return
 
-	if(carbon_source.internal)
-		carbon_source.internal = null
-
-		// This isn't meant to be FALSE, it correlates to the icon's name.
+	if (carbon_source.internal == item)
+		carbon_source.close_internals()
+	// This isn't meant to be FALSE, it correlates to the item's name.
 	else if (!QDELETED(item))
-		if((carbon_source.wear_mask?.clothing_flags & MASKINTERNALS) || carbon_source.getorganslot(ORGAN_SLOT_BREATHING_TUBE))
-			carbon_source.internal = item
+		if(!carbon_source.try_open_internals(item))
+			return
 
 	carbon_source.visible_message(
 		span_danger("[user] [isnull(carbon_source.internal) ? "closes": "opens"] the valve on [source]'s [item.name]."),

code/modules/mob/living/carbon/human/inventory.dm

@@ -287,11 +287,44 @@
 	if((I.body_parts_covered & FEET) || (I.flags_inv | I.transparent_protection) & HIDESHOES)
 		SEND_SIGNAL(src, COMSIG_CARBON_UNEQUIP_SHOECOVER, I, force, newloc, no_move, invdrop, silent)
 
+/mob/living/carbon/human/toggle_internals(obj/item/tank, is_external = FALSE)
+	// Just close the tank if it's the one the mob already has open.
+	var/obj/item/existing_tank = is_external ? external : internal
+	if(tank == existing_tank)
+		return toggle_close_internals(is_external)
+	// Use breathing tube regardless of mask.
+	if(can_breathe_tube())
+		return toggle_open_internals(tank, is_external)
+	// Use mask in absence of tube.
+	if(isclothing(wear_mask) && ((wear_mask.visor_flags & MASKINTERNALS) || (wear_mask.clothing_flags & MASKINTERNALS)))
+		// Adjust dishevelled breathing mask back onto face.
+		if (wear_mask.mask_adjusted)
+			wear_mask.adjustmask(src)
+		return toggle_open_internals(tank, is_external)
+	// Use helmet in absence of tube or valid mask.
+	if(can_breathe_helmet())
+		return toggle_open_internals(tank, is_external)
+	// Notify user of missing valid breathing apparatus.
+	if (wear_mask)
+		// Invalid mask
+		to_chat(src, span_warning("[wear_mask] can't use [tank]!"))
+	else if (head)
+		// Invalid headgear
+		to_chat(src, span_warning("[head] isn't airtight! You need a mask!"))
+	else
+		// Not wearing any breathing apparatus.
+		to_chat(src, span_warning("You need a mask!"))
+
+/// Returns TRUE if the tank successfully toggles open/closed. Opens the tank only if a breathing apparatus is found.
+/mob/living/carbon/human/toggle_externals(obj/item/tank)
+	return toggle_internals(tank, TRUE)
+
 /mob/living/carbon/human/wear_mask_update(obj/item/I, toggle_off = 1)
 	if((I.flags_inv & (HIDEHAIR|HIDEFACIALHAIR)) || (initial(I.flags_inv) & (HIDEHAIR|HIDEFACIALHAIR)))
 		update_body_parts()
-	if(toggle_off && internal && !getorganslot(ORGAN_SLOT_BREATHING_TUBE))
-		internal = null
+	// Close internal air tank if mask was the only breathing apparatus.
+	if(invalid_internals())
+		cutoff_internals()
 	if(I.flags_inv & HIDEEYES)
 		update_worn_glasses()
 	sec_hud_set_security_status()
@@ -300,6 +333,9 @@
 /mob/living/carbon/human/head_update(obj/item/I, forced)
 	if((I.flags_inv & (HIDEHAIR|HIDEFACIALHAIR)) || forced)
 		update_body_parts()
+	// Close internal air tank if helmet was the only breathing apparatus.
+	if (invalid_internals())
+		cutoff_internals()
 	if(I.flags_inv & HIDEEYES || forced)
 		update_worn_glasses()
 	if(I.flags_inv & HIDEEARS || forced)

code/modules/mob/living/carbon/human/species_types/plasmamen.dm

@@ -116,7 +116,7 @@
 /datum/species/plasmaman/pre_equip_species_outfit(datum/job/job, mob/living/carbon/human/equipping, visuals_only = FALSE)
 	if(job.plasmaman_outfit)
 		equipping.equipOutfit(job.plasmaman_outfit, visuals_only)
-	equipping.internal = equipping.get_item_for_held_index(2)
+	equipping.open_internals(equipping.get_item_for_held_index(2))
 
 /datum/species/plasmaman/random_name(gender,unique,lastname)
 	if(unique)

code/modules/mob/living/carbon/inventory.dm

@@ -168,13 +168,161 @@
 
 	// Not an else-if because we're probably equipped in another slot
 	if(I == internal && (QDELETED(src) || QDELETED(I) || I.loc != src))
-		internal = null
+		cutoff_internals()
 		if(!QDELETED(src))
 			update_action_buttons_icon(status_only = TRUE)
 
 	update_equipment_speed_mods()
 
-//handle stuff to update when a mob equips/unequips a mask.
+/// Returns TRUE if an air tank compatible helmet is equipped.
+/mob/living/carbon/proc/can_breathe_helmet()
+	if (isclothing(head) && (head.clothing_flags & HEADINTERNALS))
+		return TRUE
+
+/// Returns TRUE if an air tank compatible mask is equipped.
+/mob/living/carbon/proc/can_breathe_mask()
+	if (isclothing(wear_mask) && (wear_mask.clothing_flags & MASKINTERNALS))
+		return TRUE
+
+/// Returns TRUE if a breathing tube is equipped.
+/mob/living/carbon/proc/can_breathe_tube()
+	if (getorganslot(ORGAN_SLOT_BREATHING_TUBE))
+		return TRUE
+
+/// Returns TRUE if an air tank compatible mask or breathing tube is equipped.
+/mob/living/carbon/proc/can_breathe_internals()
+	return can_breathe_tube() || can_breathe_mask() || can_breathe_helmet()
+
+/// Returns truthy if air tank is open and mob lacks apparatus, or if the tank moved away from the mob.
+/mob/living/carbon/proc/invalid_internals()
+	return (internal || external) && (!can_breathe_internals() || (internal && internal.loc != src))
+
+/**
+ * Open the internal air tank without checking for any breathing apparatus.
+ * Returns TRUE if the air tank was opened successfully.
+ * Closes any existing tanks before opening another one.
+ *
+ * Arguments:
+ * * tank - The given tank to open and start breathing from.
+ * * is_external - A boolean which indicates if the air tank must be equipped, or stored elsewhere.
+ */
+/mob/living/carbon/proc/open_internals(obj/item/tank/target_tank, is_external = FALSE)
+	if (!target_tank)
+		return
+	close_all_airtanks()
+	if (is_external)
+		external = target_tank
+	else
+		internal = target_tank
+	target_tank.after_internals_opened(src)
+	update_action_buttons_icon()
+	return TRUE
+
+/**
+ * Opens the given internal air tank if a breathing apparatus is found. Returns TRUE if successful, FALSE otherwise.
+ * Returns TRUE if the tank was opened successfully.
+ *
+ * Arguments:
+ * * tank - The given tank we will attempt to toggle open and start breathing from.
+ * * is_external - A boolean which indicates if the air tank must be equipped, or stored elsewhere.
+ */
+/mob/living/carbon/proc/try_open_internals(obj/item/tank/target_tank, is_external = FALSE)
+	if (!can_breathe_internals())
+		return
+	return open_internals(target_tank, is_external)
+
+/**
+ * Actually closes the active internal or external air tank.
+ * Returns TRUE if the tank was opened successfully.
+ *
+ * Arguments:
+ * * is_external - A boolean which indicates if the air tank must be equipped, or stored elsewhere.
+ */
+/mob/living/carbon/proc/close_internals(is_external = FALSE)
+	var/obj/item/tank/target_tank = is_external ? external : internal
+	if (!target_tank)
+		return
+	if (is_external)
+		external = null
+	else
+		internal = null
+	target_tank.after_internals_closed(src)
+	update_action_buttons_icon()
+	return TRUE
+
+/// Close the the currently open external (that's EX-ternal) air tank. Returns TREUE if successful.
+/mob/living/carbon/proc/close_externals()
+	return close_internals(TRUE)
+
+/// Quickly/lazily close all airtanks without any returns or notifications.
+/mob/living/carbon/proc/close_all_airtanks()
+	if (external)
+		close_externals()
+	if (internal)
+		close_internals()
+
+/**
+ * Prepares to open the internal air tank and notifies the mob in chat.
+ * Handles displaying messages to the user before doing the actual opening.
+ * Returns TRUE if the tank was opened/closed successfully.
+ *
+ * Arguments:
+ * * tank - The given tank to toggle open and start breathing from.
+ * * is_external - A boolean which indicates if the air tank must be equipped, or stored elsewhere.
+ */
+/mob/living/carbon/proc/toggle_open_internals(obj/item/tank/target_tank, is_external = FALSE)
+	if (!target_tank)
+		return
+	if(internal || (is_external && external))
+		to_chat(src, span_notice("You switch your internals to [target_tank]."))
+	else
+		to_chat(src, span_notice("You open [target_tank] valve."))
+	return open_internals(target_tank, is_external)
+
+/**
+ * Prepares to close the currently open internal air tank and notifies in chat.
+ * Handles displaying messages to the user before doing the actual closing.
+ * Returns TRUE if
+ *
+ * Arguments:
+ * * is_external - A boolean which indicates if the air tank must be equipped, or stored elsewhere.
+ */
+/mob/living/carbon/proc/toggle_close_internals(is_external = FALSE)
+	if (!internal && !external)
+		return
+	to_chat(src, span_notice("You close [is_external ? external : internal] valve."))
+	return close_internals(is_external)
+
+/// Prepares emergency disconnect from open air tanks and notifies in chat. Usually called after mob suddenly unequips breathing apparatus.
+/mob/living/carbon/proc/cutoff_internals()
+	if (!external && !internal)
+		return
+	to_chat(src, span_notice("Your internals disconnect from [external || internal] and the valve closes."))
+	close_all_airtanks()
+
+/**
+ * Toggles the given internal air tank open, or close the currently open one, if a compatible breathing apparatus is found.
+ * Returns TRUE if the tank was opened successfully.
+ *
+ * Arguments:
+ * * tank - The given tank to toggle open and start breathing from internally.
+ */
+/mob/living/carbon/proc/toggle_internals(obj/item/tank)
+	// Carbons can't open their own internals tanks.
+	return FALSE
+
+/**
+ * Toggles the given external (that's EX-ternal) air tank open, or close the currently open one, if a compatible breathing apparatus is found.
+ * Returns TRUE if the tank was opened successfully.
+ *
+ * Arguments:
+ * * tank - The given tank to toggle open and start breathing from externally.
+ */
+/mob/living/carbon/proc/toggle_externals(obj/item/tank)
+	// Carbons can't open their own externals tanks.
+	return FALSE
+
+/// Handle stuff to update when a mob equips/unequips a mask.
 /mob/living/proc/wear_mask_update(obj/item/I, toggle_off = 1)
 	update_worn_mask()
 
@@ -184,7 +332,7 @@
 		update_tint()
 	update_worn_mask()
 
-//handle stuff to update when a mob equips/unequips a headgear.
+/// Handle stuff to update when a mob equips/unequips a headgear.
 /mob/living/carbon/proc/head_update(obj/item/I, forced)
 	if(isclothing(I))
 		var/obj/item/clothing/C = I

code/modules/mob/living/carbon/life.dm

@@ -151,7 +151,7 @@
 		failed_last_breath = TRUE
 		throw_alert(ALERT_NOT_ENOUGH_OXYGEN, /atom/movable/screen/alert/not_enough_oxy)
 		return FALSE
-	
+
 	var/safe_oxy_min = 16
 	var/safe_co2_max = 10
 	var/safe_plas_max = 0.05
@@ -303,21 +303,26 @@
 
 	return TRUE
 
-//Fourth and final link in a breath chain
+/// Fourth and final link in a breath chain
 /mob/living/carbon/proc/handle_breath_temperature(datum/gas_mixture/breath)
 	// The air you breathe out should match your body temperature
 	breath.temperature = bodytemperature
 
+/// Attempts to take a breath from the external or internal air tank.
 /mob/living/carbon/proc/get_breath_from_internal(volume_needed)
-	if(internal)
-		if(internal.loc != src)
-			internal = null
-		else if ((!wear_mask || !(wear_mask.clothing_flags & MASKINTERNALS)) && !getorganslot(ORGAN_SLOT_BREATHING_TUBE))
-			internal = null
-		else
-			. = internal.remove_air_volume(volume_needed)
-			if(!.)
-				return FALSE //to differentiate between no internals and active, but empty internals
+	if(invalid_internals())
+		// Unexpectely lost breathing apparatus and ability to breathe from the internal air tank.
+		cutoff_internals()
+		return
+	if (external)
+		. = external.remove_air_volume(volume_needed)
+	else if (internal)
+		. = internal.remove_air_volume(volume_needed)
+	else
+		// Return without taking a breath if there is no air tank.
+		return
+	// To differentiate between no internals and active, but empty internals.
+	return . || FALSE
 
 /mob/living/carbon/proc/handle_blood(delta_time, times_fired)
 	return

code/modules/mod/mod_activation.dm

@@ -220,6 +220,9 @@
 		wearer.update_worn_mask()
 		wearer.update_worn_glasses()
 		wearer.update_body_parts()
+		// Close internal air tank if MOD helmet is unsealed and was the only breathing apparatus.
+		if (!seal && wearer?.invalid_internals())
+			wearer.cutoff_internals()
 
 /// Finishes the suit's activation, starts processing
 /obj/item/mod/control/proc/finish_activation(on)

code/modules/mod/mod_control.dm

@@ -444,7 +444,7 @@
 	icon_state = "[skin]-control[active ? "-sealed" : ""]"
 	return ..()
 
-/obj/item/mod/control/proc/set_wearer(mob/user)
+/obj/item/mod/control/proc/set_wearer(mob/living/carbon/human/user)
 	wearer = user
 	SEND_SIGNAL(src, COMSIG_MOD_WEARER_SET, wearer)
 	RegisterSignal(wearer, COMSIG_ATOM_EXITED, .proc/on_exit)

code/modules/mod/mod_theme.dm

@@ -55,7 +55,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				SEALED_INVISIBILITY =  HIDEFACIALHAIR|HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
 			),
@@ -79,7 +79,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				UNSEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
 			),
@@ -126,7 +126,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -174,7 +174,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDESNOUT,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR,
 				UNSEALED_COVER = HEADCOVERSMOUTH,
@@ -228,7 +228,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -293,7 +293,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEEARS|HIDEHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEYES|HIDEFACE|HIDEFACIALHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -318,7 +318,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEEARS|HIDEHAIR|HIDESNOUT,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEYES|HIDEFACE,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -424,7 +424,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -449,7 +449,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -509,7 +509,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -564,7 +564,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				UNSEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
 			),
@@ -613,7 +613,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEEARS|HIDEHAIR|HIDESNOUT,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEYES|HIDEFACE,
 				UNSEALED_COVER = HEADCOVERSMOUTH,
@@ -665,7 +665,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				UNSEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
 			),
@@ -720,7 +720,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -768,7 +768,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEEARS|HIDEHAIR,
 				SEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEYES|HIDEFACE|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -824,7 +824,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -849,7 +849,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -905,7 +905,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -1014,7 +1014,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL|CASTING_CLOTHES,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				UNSEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
 			),
@@ -1066,7 +1066,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEEARS|HIDEHAIR,
 				SEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEYES|HIDEFACE|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -1120,7 +1120,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				UNSEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
 			),
@@ -1170,7 +1170,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -1195,7 +1195,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				UNSEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
 			),
@@ -1247,7 +1247,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEEARS|HIDEHAIR,
 				SEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEMASK|HIDEEYES|HIDEFACE|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -1298,7 +1298,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEEARS|HIDEHAIR|HIDESNOUT,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEYES|HIDEFACE,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -1343,7 +1343,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = NECK_LAYER,
 				UNSEALED_CLOTHING = SNUG_FIT,
-				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE|HIDEHAIR|HIDESNOUT,
 				SEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,
@@ -1389,7 +1389,7 @@
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
 				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL,
-				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				SEALED_CLOTHING = STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEEARS|HIDEHAIR|HIDESNOUT,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE,
 				UNSEALED_COVER = HEADCOVERSMOUTH,
@@ -1437,7 +1437,7 @@
 		"debug" = list(
 			HELMET_FLAGS = list(
 				UNSEALED_LAYER = null,
-				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT,
+				UNSEALED_CLOTHING = SNUG_FIT|THICKMATERIAL|STOPSPRESSUREDAMAGE|BLOCK_GAS_SMOKE_EFFECT|HEADINTERNALS,
 				UNSEALED_INVISIBILITY = HIDEFACIALHAIR|HIDEEARS|HIDEHAIR|HIDESNOUT,
 				SEALED_INVISIBILITY = HIDEMASK|HIDEEARS|HIDEEYES|HIDEFACE,
 				UNSEALED_COVER = HEADCOVERSMOUTH|HEADCOVERSEYES|PEPPERPROOF,