Rice is useful. Some people take the 2 - 5 pound bags, nuke them, and place them on sore backs or other places. The bags are large enough to stay put (and not wander) and they hold heat. This was done for me. I have not done this for myself/by myself.
Anyway, after work and the grocery store (not a shop), I am at home and doing some of the endless little jobs around the house.
My garden in England is full of eating-out places, for heat waves, warm September evenings, or lunch on a chilly Christmas morning. (Mary Quant)