well gnomsky was expressing his concern about making boom boom, and I made a comment about getting a splinter in the wee wee, and it started escalating
but to actually contribute to the topic, no I've never slept on a hard surface (actually I probably have, but whatever). A good option might be a nice air mattress. I slept on one for months until I adopted a cat that started stretching on it with his claws.
also, a mattress isn't hotter because it absorbs heat. a mattress is largely air, which an insulator. It conducts heat very poorly, so it stays in the body. on the other hand, a wooden board conducts heat much better, meaning it'll take it away from your body much easier.