Hello, I'm a a new custodian of two desert tortoises. We think they are about a year old each. I live about a quarter mile from the ocean in San Diego. The weather is mild and usually around 70+, however, we do get the coastal fog every morning that sometimes never burns off all day. Currently, the tortoises stay in a nice big outdoor enclosure during the day and I bring them in at night. I recently purchased an outdoor heating pad but I'm not sure how or when to use it. They have an outdoor house but I'm uneasy about putting the pad directly under the house. I need some guidance here. When should I have the heating pad on and where should I put it? Thanks for your help and suggestions.