Ports Snowy stuff from Eros

code/__defines/math_physics.dm

@@ -15,9 +15,10 @@
 #define RADIATOR_EXPOSED_SURFACE_AREA_RATIO 0.04 // (3 cm + 100 cm * sin(3deg))/(2*(3+100 cm)). Unitless ratio.
 #define HUMAN_EXPOSED_SURFACE_AREA          5.2 //m^2, surface area of 1.7m (H) x 0.46m (D) cylinder
 
-#define T0C  273.15 //    0.0 degrees celcius
-#define T20C 293.15 //   20.0 degrees celcius
-#define TCMB 2.7    // -270.3 degrees celcius
+#define T0C  273.15  //    0.0 degrees celcius
+#define T20C 293.15  //   20.0 degrees celcius
+#define TCMB 2.7     // -270.3 degrees celcius
+#define TN60C 213.15 //    -60 degrees celcius
 
 #define CLAMP01(x) max(0, min(1, x))
 #define QUANTIZE(variable) (round(variable,0.0001))

code/game/turfs/snow/snow.dm

@@ -0,0 +1,34 @@
+/turf/snow
+    name = "snow"
+
+    dynamic_lighting = 0
+    icon = 'icons/turf/snow_new.dmi'
+    icon_state = "snow"
+
+    oxygen = MOLES_O2STANDARD * 1.15
+    nitrogen = MOLES_N2STANDARD * 1.15
+
+    temperature = TN60C
+    var/list/crossed_dirs = list()
+
+#define FOOTSTEP_SPRITE_AMT 2
+
+/turf/snow/Entered(atom/A)
+    if(ismob(A))
+        var/mdir = "[A.dir]"
+        if(crossed_dirs[mdir])
+            crossed_dirs[mdir] = min(crossed_dirs[mdir] + 1, FOOTSTEP_SPRITE_AMT)
+        else
+            crossed_dirs[mdir] = 1
+
+        update_icon()
+
+    . = ..()
+
+/turf/snow/update_icon()
+    overlays.Cut()
+    for(var/d in crossed_dirs)
+        var/amt = crossed_dirs[d]
+
+        for(var/i in 1 to amt)
+            overlays += icon(icon, "footprint[i]", text2num(d))

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

@@ -619,11 +619,11 @@
 		if(!istype(loc, /obj/machinery/atmospherics/unary/cryo_cell))
 			var/burn_dam = 0
 			switch(bodytemperature)
-				if(-INFINITY to species.cold_level_3)
+				if(species.cold_level_1 to species.cold_level_2)
 					burn_dam = COLD_DAMAGE_LEVEL_1
-				if(species.cold_level_3 to species.cold_level_2)
+				if(species.cold_level_2 to species.cold_level_3)
 					burn_dam = COLD_DAMAGE_LEVEL_2
-				if(species.cold_level_2 to species.cold_level_1)
+				if(species.cold_level_3 to -INFINITY)
 					burn_dam = COLD_DAMAGE_LEVEL_3
 			take_overall_damage(burn=burn_dam, used_weapon = "Low Body Temperature")
 			fire_alert = max(fire_alert, 1)
@@ -847,9 +847,9 @@
 	if(!isSynthetic() && (species.flags & IS_PLANT) && (!light_organ || light_organ.is_broken()))
 		if(nutrition < 200)
 			take_overall_damage(2,0)
-			
-			//traumatic_shock is updated every tick, incrementing that is pointless - shock_stage is the counter. 
-			//Not that it matters much for diona, who have NO_PAIN. 
+
+			//traumatic_shock is updated every tick, incrementing that is pointless - shock_stage is the counter.
+			//Not that it matters much for diona, who have NO_PAIN.
 			shock_stage++
 
 	// TODO: stomach and bloodstream organ.