Cooling Blankets - Fever Blankets
It’s more substantial than a sheet and actively cools you when you’re hot by wicking away your sweat and letting your skin breathe. (That’s why a lot of hot countries traditionally wear clothes made from linen.) When you’re too cold, it also is able to insulate you, to stop you getting cold. Yes, it does sound a little bit like magic, but to be fair, it is that good.