Hi,
I don't know how old your baby is, but dragons need darkness at night to sleep in - red or colored lights typically intefere with their sleep. If you house is going below 65-68 degrees at night, then consider a heating pad (stuck to the side, not the bottom) or a ceramic heat emitter that doesn't give off any light during sleep time. Otherwise, if you are at or above 68, you should be fine w/o anything. Mine has a heating pad stuck to the back of the tank that kicks on at night and keeps her tank at 72 on the warm side and 68 on the cool side. Her lights turn on in the am at 5:15 and shut off in the evening at 7:15 pm.
Most folks say in the summer it's 14 hours on, 10 hours dark, winter, scale back to 12 on and 12 off.