Marina:
Air conditioning, fans (both oscillating and hand held) deodorant on the small of the back, inner thighs, and underboob. Helps immensely!
I never thought about putting deodorant in the small of my back (not sure if I could even reach it to be honest). When you say inner thighs, how high up are we talking about. Some folks say that knickers help with thigh rub, but it seems that they would be hot in summer, with the extra bulk.