Adds suit cooling device

Also:

Breathing in hot/cold air will affect your body temperature.
Fixes old body temperature stabilization code not working.
Thermometer icon now adjusts based on species.
Reduced BODYTEMP_AUTORECOVERY_MINIMUM to a less ridiculous value.

code/game/objects/items/devices/suit_cooling.dm

@@ -0,0 +1,161 @@
+/obj/item/device/suit_cooling_unit
+	name = "portable suit cooling unit"
+	desc = "A portable heat sink and liquid cooled radiator that can be hooked up to a space suit's existing temperature controls to provide industrial levels of cooling."
+	w_class = 4
+	icon = 'icons/obj/power.dmi'	//temporary, I hope
+	icon_state = "portgen0"
+	slot_flags = SLOT_BACK	//you can carry it on your back if you want, but it won't do anything unless attached to suit storage
+	
+	var/on = 0				//is it turned on?
+	var/cover_open = 0		//is the cover open?
+	var/obj/item/weapon/cell/cell
+	var/max_cooling = 12				//in degrees per second - probably don't need to mess with heat capacity here
+	var/charge_consumption = 16.6		//charge per second at max_cooling
+	var/thermostat = T20C
+	
+	//TODO: make it heat up the surroundings when not in space
+
+/obj/item/device/suit_cooling_unit/proc/cool_mob(mob/M)
+	if (!on || !cell) return
+	
+	//make sure they have a suit and we are attached to it
+	if (!attached_to_suit(M))
+		return
+	
+	var/mob/living/carbon/human/H = M
+	
+	var/efficiency = H.get_pressure_protection()		//you need to have a good seal for effective cooling
+	var/env_temp = get_environment_temperature()		//wont save you from a fire
+	var/temp_adj = min(H.bodytemperature - max(thermostat, env_temp), max_cooling)
+	
+	if (temp_adj < 0)	//only cools, doesn't heat
+		return
+	
+	var/charge_usage = (temp_adj/max_cooling)*charge_consumption
+	
+	H.bodytemperature -= temp_adj*efficiency
+	
+	cell.use(charge_usage)
+	
+	if(cell.charge <= 0)
+		turn_off()
+
+/obj/item/device/suit_cooling_unit/proc/get_environment_temperature()
+	if (ishuman(loc))
+		var/mob/living/carbon/human/H = loc
+		if(istype(H.loc, /obj/mecha))
+			var/obj/mecha/M = loc
+			return M.return_temperature()
+		else if(istype(H.loc, /obj/machinery/atmospherics/unary/cryo_cell))
+			return H.loc:air_contents.temperature
+
+	var/turf/T = get_turf(src)
+	if(istype(T, /turf/space))
+		return 0	//space has no temperature, this just makes sure the cooling unit works in space
+	
+	var/datum/gas_mixture/environment = T.return_air()
+	if (!environment)
+		return 0
+	
+	return environment.temperature
+
+/obj/item/device/suit_cooling_unit/proc/attached_to_suit(mob/M)
+	if (!ishuman(M)) 
+		return 0
+	
+	var/mob/living/carbon/human/H = M
+	
+	if (!H.wear_suit || H.s_store != src)
+		return 0
+	
+	return 1
+
+/obj/item/device/suit_cooling_unit/proc/turn_on()
+	if(!cell)
+		return
+	if(cell.charge <= 0)
+		return
+	
+	on = 1
+	updateicon()
+
+/obj/item/device/suit_cooling_unit/proc/turn_off()
+	if (ismob(src.loc))
+		src.loc << "\The [src] clicks and whines as it powers down."	//let them know
+	on = 0
+	updateicon()
+
+/obj/item/device/suit_cooling_unit/attack_self(mob/user as mob)
+	if(cover_open && cell)
+		if(ishuman(user))
+			user.put_in_hands(cell)
+		else
+			cell.loc = get_turf(loc)
+
+		cell.add_fingerprint(user)
+		cell.updateicon()
+
+		user << "You remove the [src.cell]."
+		src.cell = null
+		updateicon()
+		return
+
+	//TODO use a UI like the air tanks
+	if(on)
+		turn_off()
+	else
+		turn_on()
+		if (on)
+			user << "You switch on the [src]."
+
+/obj/item/device/suit_cooling_unit/attackby(obj/item/weapon/W as obj, mob/user as mob)
+	if (istype(W, /obj/item/weapon/screwdriver))
+		if(cover_open)
+			cover_open = 0
+			user << "You screw the panel into place."
+		else
+			cover_open = 1
+			user << "You unscrew the panel."
+		updateicon()
+		return
+
+	if (istype(W, /obj/item/weapon/cell))
+		if(cover_open)
+			if(cell)
+				user << "There is a [cell] already installed here."
+			else
+				user.drop_item()
+				W.loc = src
+				cell = W
+				user << "You insert the [cell]."
+		updateicon()
+		return
+	
+	return ..()
+
+/obj/item/device/suit_cooling_unit/proc/updateicon()
+	return 0	//TODO
+
+/obj/item/device/suit_cooling_unit/examine()
+	set src in view(1)
+	
+	..()
+	
+	if (on)
+		if (attached_to_suit(src.loc))
+			usr << "It's switched on and running."
+		else
+			usr << "It's switched on, but not attached to anything."
+	else
+		usr << "It is switched off."
+	
+	if (cover_open)
+		if(cell)
+			usr << "The panel is open, exposing the [cell]."
+		else
+			usr << "The panel is open."
+	
+	if (cell)
+		usr << "The charge meter reads [round(cell.percent())]%."
+	else
+		usr << "It doesn't have a power cell installed."

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

@@ -6,6 +6,7 @@
 	icon = 'icons/obj/tank.dmi'
 	flags = FPRINT | TABLEPASS | CONDUCT
 	slot_flags = SLOT_BACK
+	w_class = 3
 
 	pressure_resistance = ONE_ATMOSPHERE*5