After cooking steaks from a deer and a boar, I placed them in my blue tent. They were still hot hours later. I took one out and left it in my equipped backpack. It cooled down normally. I took another hot steak out of the tent and put it in a different blue tent, and took a third hot steak from the first tent and put it in a barrel. Neither steak cooled down, both were still hot hours later.

I also put away hot the cooking pot I used for the steaks, at the same time. It cooled normally. I have not tested a hot steak in a backpack on the ground. I did try leaving the inventory menu open, watching the hot steaks in the tent. They did not cool down.