I'm not even sure if this is even related to Cold Sweat but I'd like to confirm with the Cold Sweat devs.

Issue:

Dying from -100 or 100 temperature will not drop your items from your inventory (All of it). They are basically deleted from the world.
This does not occur if less than -100 or 100 temperatures.

Mods:

FirstAid 1.11.1
ColdSweat-2.2-b04a.jar

Thanks for posting. I was able to find the issue, and a fix will be making its way into the next beta (b04b).

Thank you!