Typecheck all return_air calls (#15363)

code/modules/mob/abstract/observer/observer.dm

@@ -540,6 +540,7 @@ This is the proc mobs get to turn into a ghost. Forked from ghostize due to comp
 			continue
 
 		var/turf/T = get_turf(testvent)
+		if(!istype(T)) continue
 
 		//Skip areas that contain turrets
 		var/area/A = T.loc

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

@@ -1200,6 +1200,8 @@ mob/living/carbon/human/proc/change_monitor()
 	else
 		custom_emote(VISIBLE_MESSAGE, "flicks their tongue out.")
 
+	if(!src.loc) return
+
 	var/datum/gas_mixture/mixture = src.loc.return_air()
 	var/total_moles = mixture.total_moles
 
@@ -1317,4 +1319,4 @@ mob/living/carbon/human/proc/change_monitor()
 /mob/living/carbon/human/proc/stop_listening()
 	if (is_listening())
 		visible_message("<b>[src]</b> stops listening intently.")
-		intent_listener -= src
+		intent_listener -= src

code/modules/mob/living/living_defense.dm

@@ -280,6 +280,10 @@
 	return fire_stacks
 
 /mob/living/proc/handle_fire()
+	if(!loc)
+		ExtinguishMobCompletely()
+		return TRUE
+
 	if(fire_stacks < 0)
 		fire_stacks = min(0, ++fire_stacks) //If we've doused ourselves in water to avoid fire, dry off slowly