The government program ENERGY STAR recommends 70 for heat and 78 for cool. They recommend installing a programmable thermostat to only maintain the temperature when you are there.emperature: 65-70 F degrees; with 65% humidity. Surely this depends on what one is used to. I find sleep most refreshing when I sleep at a lower temperature than the above … answer, say 58-60F. Recent (2003-2006) sleep studies at several USA universities confirm the popularity of the top answer.