diff --git a/code/modules/mob/living/carbon/human/life.dm b/code/modules/mob/living/carbon/human/life.dm
index 72c281a1f2d..8657ef06a26 100644
--- a/code/modules/mob/living/carbon/human/life.dm
+++ b/code/modules/mob/living/carbon/human/life.dm
@@ -599,34 +599,37 @@
 			adjustOxyLoss(-5)
 
 		// Hot air hurts :(
-		if( (breath.temperature < species.cold_level_1 || breath.temperature > species.heat_level_1) && !(COLD_RESISTANCE in mutations))
+		if( (breath.temperature <= species.cold_level_1 || breath.temperature >= species.heat_level_1) && !(COLD_RESISTANCE in mutations))
 
-			if(breath.temperature < species.cold_level_1)
+			if(breath.temperature <= species.cold_level_1)
 				if(prob(20))
 					src << "<span class='danger'>You feel your face freezing and icicles forming in your lungs!</span>"
-			else if(breath.temperature > species.heat_level_1)
+			else if(breath.temperature >= species.heat_level_1)
 				if(prob(20))
 					src << "<span class='danger'>You feel your face burning and a searing heat in your lungs!</span>"
 
-			switch(breath.temperature)
-				if(-INFINITY to species.cold_level_3)
-					apply_damage(COLD_GAS_DAMAGE_LEVEL_3, BURN, "head", used_weapon = "Excessive Cold")
-					fire_alert = max(fire_alert, 1)
-				if(species.cold_level_3 to species.cold_level_2)
-					apply_damage(COLD_GAS_DAMAGE_LEVEL_2, BURN, "head", used_weapon = "Excessive Cold")
-					fire_alert = max(fire_alert, 1)
-				if(species.cold_level_2 to species.cold_level_1)
-					apply_damage(COLD_GAS_DAMAGE_LEVEL_1, BURN, "head", used_weapon = "Excessive Cold")
-					fire_alert = max(fire_alert, 1)
-				if(species.heat_level_1 to species.heat_level_2)
+			if(breath.temperature >= species.heat_level_1)
+				if(breath.temperature < species.heat_level_2)
 					apply_damage(HEAT_GAS_DAMAGE_LEVEL_1, BURN, "head", used_weapon = "Excessive Heat")
 					fire_alert = max(fire_alert, 2)
-				if(species.heat_level_2 to species.heat_level_3)
+				else if(breath.temperature < species.heat_level_3)
 					apply_damage(HEAT_GAS_DAMAGE_LEVEL_2, BURN, "head", used_weapon = "Excessive Heat")
 					fire_alert = max(fire_alert, 2)
-				if(species.heat_level_3 to INFINITY)
+				else
 					apply_damage(HEAT_GAS_DAMAGE_LEVEL_3, BURN, "head", used_weapon = "Excessive Heat")
 					fire_alert = max(fire_alert, 2)
+			
+			else if(breath.temperature <= species.cold_level_1)
+				if(breath.temperature > species.cold_level_2)
+					apply_damage(COLD_GAS_DAMAGE_LEVEL_1, BURN, "head", used_weapon = "Excessive Cold")
+					fire_alert = max(fire_alert, 1)
+				else if(breath.temperature > species.cold_level_3)
+					apply_damage(COLD_GAS_DAMAGE_LEVEL_2, BURN, "head", used_weapon = "Excessive Cold")
+					fire_alert = max(fire_alert, 1)
+				else
+					apply_damage(COLD_GAS_DAMAGE_LEVEL_3, BURN, "head", used_weapon = "Excessive Cold")
+					fire_alert = max(fire_alert, 1)
+
 
 			//breathing in hot/cold air also heats/cools you a bit
 			var/temp_adj = breath.temperature - bodytemperature
@@ -692,43 +695,38 @@
 
 			//Use heat transfer as proportional to the gas density. However, we only care about the relative density vs standard 101 kPa/20 C air. Therefore we can use mole ratios
 			var/relative_density = environment.total_moles / MOLES_CELLSTANDARD
-			temp_adj *= relative_density
-
-			if (temp_adj > BODYTEMP_HEATING_MAX) temp_adj = BODYTEMP_HEATING_MAX
-			if (temp_adj < BODYTEMP_COOLING_MAX) temp_adj = BODYTEMP_COOLING_MAX
-			//world << "Environment: [loc_temp], [src]: [bodytemperature], Adjusting: [temp_adj]"
-			bodytemperature += temp_adj
+			bodytemperature += between(BODYTEMP_COOLING_MAX, temp_adj*relative_density, BODYTEMP_HEATING_MAX)
 
 		// +/- 50 degrees from 310.15K is the 'safe' zone, where no damage is dealt.
-		if(bodytemperature > species.heat_level_1)
+		if(bodytemperature >= species.heat_level_1)
 			//Body temperature is too hot.
 			fire_alert = max(fire_alert, 1)
 			if(status_flags & GODMODE)	return 1	//godmode
-			switch(bodytemperature)
-				if(species.heat_level_1 to species.heat_level_2)
-					take_overall_damage(burn=HEAT_DAMAGE_LEVEL_1, used_weapon = "High Body Temperature")
-					fire_alert = max(fire_alert, 2)
-				if(species.heat_level_2 to species.heat_level_3)
-					take_overall_damage(burn=HEAT_DAMAGE_LEVEL_2, used_weapon = "High Body Temperature")
-					fire_alert = max(fire_alert, 2)
-				if(species.heat_level_3 to INFINITY)
-					take_overall_damage(burn=HEAT_DAMAGE_LEVEL_3, used_weapon = "High Body Temperature")
-					fire_alert = max(fire_alert, 2)
+			
+			if(bodytemperature < species.heat_level_2)
+				take_overall_damage(burn=HEAT_DAMAGE_LEVEL_1, used_weapon = "High Body Temperature")
+				fire_alert = max(fire_alert, 2)
+			else if(bodytemperature < species.heat_level_3)
+				take_overall_damage(burn=HEAT_DAMAGE_LEVEL_2, used_weapon = "High Body Temperature")
+				fire_alert = max(fire_alert, 2)
+			else
+				take_overall_damage(burn=HEAT_DAMAGE_LEVEL_3, used_weapon = "High Body Temperature")
+				fire_alert = max(fire_alert, 2)
 
-		else if(bodytemperature < species.cold_level_1)
+		else if(bodytemperature <= species.cold_level_1)
 			fire_alert = max(fire_alert, 1)
 			if(status_flags & GODMODE)	return 1	//godmode
+			
 			if(!istype(loc, /obj/machinery/atmospherics/unary/cryo_cell))
-				switch(bodytemperature)
-					if(species.cold_level_2 to species.cold_level_1)
-						take_overall_damage(burn=COLD_DAMAGE_LEVEL_1, used_weapon = "High Body Temperature")
-						fire_alert = max(fire_alert, 1)
-					if(species.cold_level_3 to species.cold_level_2)
-						take_overall_damage(burn=COLD_DAMAGE_LEVEL_2, used_weapon = "High Body Temperature")
-						fire_alert = max(fire_alert, 1)
-					if(-INFINITY to species.cold_level_3)
-						take_overall_damage(burn=COLD_DAMAGE_LEVEL_3, used_weapon = "High Body Temperature")
-						fire_alert = max(fire_alert, 1)
+				if(bodytemperature > species.cold_level_2)
+					take_overall_damage(burn=COLD_DAMAGE_LEVEL_1, used_weapon = "High Body Temperature")
+					fire_alert = max(fire_alert, 1)
+				else if(bodytemperature > species.cold_level_3)
+					take_overall_damage(burn=COLD_DAMAGE_LEVEL_2, used_weapon = "High Body Temperature")
+					fire_alert = max(fire_alert, 1)
+				else
+					take_overall_damage(burn=COLD_DAMAGE_LEVEL_3, used_weapon = "High Body Temperature")
+					fire_alert = max(fire_alert, 1)
 
 		// Account for massive pressure differences.  Done by Polymorph
 		// Made it possible to actually have something that can protect against high pressure... Done by Errorage. Polymorph now has an axe sticking from his head for his previous hardcoded nonsense!