Im using a light sitting on top of the screen and i have the foil on all of the screen with the black duck tape covering the foil. my temp gage in side the cage reads 90 during the day and when i shut the light off at night sometimes i notice in the morning that the temp gage reads 65-70 that seems cool to me but my pet store told me that was fine because what do you think snakes do at night out side ! So should i be using another heat source along with something at night to keep her warm. thank you stacy