My Leos have gone through periods of cooling due to a failed thermostat and they were okay until I got my new one a few days later. Just don't feed him during that time period because they need a belly heat temperature of 95° for digestion purpose. When you get him though make sure the warm side is a constant 93-95° to aid in digestion. I keep mine in 15qt hefty tubs one a rack with heat cable attached to a thermostat. Their temp is always 95-96° on the hot side and 85° the cold side. Crickets don't have much nutritional value for Leos. I would suggest gutloaded mealworms and superworms. If you can swing it dubia roaches are even better! The ocassional pinky mouse dipped in calcium is good too. Make sure there is calcium out on the cage at all times, And dust every meal. They are really notorious for MBD. Hope this helps. Keep us updated.