I heated up a very large plastic bowl of water for 8 minutes in the microwave just now, and then poured it hot into a flat plastic bin. I was able to get both feet in them up to the low ankles and then squat down and get my hands in there too. So i just enjoyed the heat for awhile, and then took a sponge bath and shaved my legs.

I didn't have enough hot water for my hair with this set up, but for a mini-bath, it was reasonable.

I had to futz around with water amounts and microwave time amounts and various containers to make this work. So if someone needs to experiment with this, don't get discouraged right away. Keep tweaking.