I have a themostat to control her UTH and I have her old thermometer to check her air temp. The lowest Ive seen it go is around 77 at night when her daylight lamp is off. I havent had to use daylight lamp in her old tank cause she was on the opposite side of the room. Now shes closer to the window so Im thinking it would be a bit colder. She eats small rats right now, she has taken them even before moving.