every room and every cage/tank/tub or rack setup can be different. that's why thermostats and thermometers are needed to check and get things right.
the ambient temp in the area/room the snakes are in are vital to how and what you heat with. i'm a big fan of keeping the temps and humidity in my room stable this keeps everything right. i know not everyone has a spare room, but the same can be done with any area you keep your herps in. a small space heater and a small humidifier can help alot with ambient and cool side temps and the dry air of winter.

vaughn