Ideally you want the heat to come from up above with heat lamps but I don't usually recommend it because some people new to frogs have cooked their frogs this way. But if you live in a cold climate you are probably going to have to go that route. I would use a Thermostat to make sure it stays at the temperature that you want. I would say keep your Red Eyes around the 78 degree range with a 5 degree drop at night. I agree with Martin you want to have lots of live plants not only for them to climb on but it also helps you to maintain a consistent humidity. With a ton of plants and the moss on the bottom you will have happy and healthy frogs. They will be able to move to different parts of the terrarium where it is cooler or warmer or more humid. Check out the ZooMed Hygro Therm. It monitors your humidity and your temps and will turn on and off your devices to help maintain exactly what you set it at. It can also be programed to have drops in those readings at night. In the US they are around $75. That way you can plug in your heating device and mister and it will maintain your readings for you, turning them on and off as necessary.