diff --git a/code/__DEFINES/atmospherics.dm b/code/__DEFINES/atmospherics.dm
index f9c3b0d427..2b19b557b2 100644
--- a/code/__DEFINES/atmospherics.dm
+++ b/code/__DEFINES/atmospherics.dm
@@ -298,6 +298,8 @@ GLOBAL_LIST_INIT(atmos_adjacent_savings, list(0,0))
 
 #define ARCHIVE_TEMPERATURE(gas) gas.temperature_archived = gas.temperature
 
+#define ARCHIVE(gas) gas.temperature_archived = gas.temperature; gas.gas_archive = gas.gases.Copy();
+
 GLOBAL_LIST_INIT(pipe_paint_colors, list(
 		"amethyst" = rgb(130,43,255), //supplymain
 		"blue" = rgb(0,0,255),
diff --git a/code/modules/atmospherics/environmental/LINDA_turf_tile.dm b/code/modules/atmospherics/environmental/LINDA_turf_tile.dm
index 632542f605..081f0b1d28 100644
--- a/code/modules/atmospherics/environmental/LINDA_turf_tile.dm
+++ b/code/modules/atmospherics/environmental/LINDA_turf_tile.dm
@@ -89,7 +89,7 @@
 	temperature_archived = temperature
 
 /turf/open/archive()
-	ARCHIVE_TEMPERATURE(air)
+	ARCHIVE(air)
 	archived_cycle = SSair.times_fired
 	temperature_archived = temperature
 
@@ -215,7 +215,7 @@
 	if (planet_atmos) //share our air with the "atmosphere" "above" the turf
 		var/datum/gas_mixture/G = new
 		G.copy_from_turf(src)
-		ARCHIVE_TEMPERATURE(G)
+		ARCHIVE(G)
 		if(our_air.compare(G))
 			if(!our_excited_group)
 				var/datum/excited_group/EG = new
diff --git a/code/modules/atmospherics/gasmixtures/gas_mixture.dm b/code/modules/atmospherics/gasmixtures/gas_mixture.dm
index 5ff8586c34..93927f4420 100644
--- a/code/modules/atmospherics/gasmixtures/gas_mixture.dm
+++ b/code/modules/atmospherics/gasmixtures/gas_mixture.dm
@@ -17,6 +17,7 @@ GLOBAL_LIST_INIT(meta_gas_ids, meta_gas_id_list())
 GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 /datum/gas_mixture
 	var/list/gases = list()
+	var/list/gas_archive = list()
 	var/temperature = 0 //kelvins
 	var/tmp/temperature_archived = 0
 	var/volume = CELL_VOLUME //liters
@@ -31,13 +32,25 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 
 	//PV = nRT
 
-/datum/gas_mixture/proc/heat_capacity() //joules per kelvin
+/datum/gas_mixture/proc/heat_capacity()
+
+/datum/gas_mixture/proc/archived_heat_capacity()
+
+/datum/gas_mixture/heat_capacity() //joules per kelvin
 	var/list/cached_gases = gases
 	var/list/cached_gasheats = GLOB.meta_gas_specific_heats
 	. = 0
 	for(var/id in cached_gases)
 		. += cached_gases[id] * cached_gasheats[id]
 
+/datum/gas_mixture/archived_heat_capacity()
+	// lots of copypasta but heat_capacity is the single proc called the most in a regular round, bar none, so performance loss adds up
+	var/list/cached_gases = gas_archive
+	var/list/cached_gasheats = GLOB.meta_gas_specific_heats
+	. = 0
+	for(var/id in cached_gases)
+		. += cached_gases[id] * cached_gasheats[id]
+
 /datum/gas_mixture/turf/heat_capacity() // Same as above except vacuums return HEAT_CAPACITY_VACUUM
 	var/list/cached_gases = gases
 	var/list/cached_gasheats = GLOB.meta_gas_specific_heats
@@ -46,6 +59,14 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 	if(!.)
 		. += HEAT_CAPACITY_VACUUM //we want vacuums in turfs to have the same heat capacity as space
 
+/datum/gas_mixture/turf/archived_heat_capacity() // Same as above except vacuums return HEAT_CAPACITY_VACUUM
+	var/list/cached_gases = gas_archive
+	var/list/cached_gasheats = GLOB.meta_gas_specific_heats
+	for(var/id in cached_gases)
+		. += cached_gases[id] * cached_gasheats[id]
+	if(!.)
+		. += HEAT_CAPACITY_VACUUM //we want vacuums in turfs to have the same heat capacity as space
+
 /datum/gas_mixture/proc/total_moles()
 	var/cached_gases = gases
 	TOTAL_MOLES(cached_gases, .)
@@ -67,6 +88,10 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 /datum/gas_mixture/proc/thermal_energy() //joules
 	return THERMAL_ENERGY(src) //see code/__DEFINES/atmospherics.dm; use the define in performance critical areas
 
+/datum/gas_mixture/proc/archive()
+	//Update archived versions of variables
+	//Returns: 1 in all cases
+
 /datum/gas_mixture/proc/merge(datum/gas_mixture/giver)
 	//Merges all air from giver into self. Deletes giver.
 	//Returns: 1 if we are mutable, 0 otherwise
@@ -111,6 +136,10 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 	//Performs various reactions such as combustion or fusion (LOL)
 	//Returns: 1 if any reaction took place; 0 otherwise
 
+/datum/gas_mixture/archive()
+	temperature_archived = temperature
+	gas_archive = gases.Copy()
+	return 1
 
 /datum/gas_mixture/merge(datum/gas_mixture/giver)
 	if(!giver)
@@ -245,7 +274,7 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 	//GAS TRANSFER
 	for(var/id in cached_gases | sharer_gases) // transfer gases
 
-		delta = QUANTIZE(cached_gases[id] - sharer_gases[id])/(atmos_adjacent_turfs+1) //the amount of gas that gets moved between the mixtures
+		delta = QUANTIZE(gas_archive[id] - sharer.gas_archive[id])/(atmos_adjacent_turfs+1) //the amount of gas that gets moved between the mixtures
 
 		if(delta && abs_temperature_delta > MINIMUM_TEMPERATURE_DELTA_TO_CONSIDER)
 			gas_heat_capacity = delta * cached_gasheats[id]
@@ -293,8 +322,8 @@ GLOBAL_LIST_INIT(meta_gas_fusions, meta_gas_fusion_list())
 		sharer_temperature = sharer.temperature_archived
 	var/temperature_delta = temperature_archived - sharer_temperature
 	if(abs(temperature_delta) > MINIMUM_TEMPERATURE_DELTA_TO_CONSIDER)
-		var/self_heat_capacity = heat_capacity()
-		sharer_heat_capacity = sharer_heat_capacity || sharer.heat_capacity()
+		var/self_heat_capacity = archived_heat_capacity()
+		sharer_heat_capacity = sharer_heat_capacity || sharer.archived_heat_capacity()
 
 		if((sharer_heat_capacity > MINIMUM_HEAT_CAPACITY) && (self_heat_capacity > MINIMUM_HEAT_CAPACITY))
 			var/heat = conduction_coefficient*temperature_delta* \