75 is a bit low but as long as the snake has a warm side he can go to, he should be fine. Same goes for a hot side, if they don't have somewhere to escape that heat, problems will arise. Its the reason snakes thermo regulate. Honestly, I don't get that technical into it. I give all my gals a warm side of 86-88F and a cool side of 78-80F and they do the rest as needed