Another possibility that can make a world of difference is if a warmer room exists in the house move him to it. Also keep the tank away from windows in your house. Sitting next to a window in this kind of weather in my house makes me cold. Limit drafts, make sure no heater vent blows on the aquarium and it is not next to a cold air intake. (as long as you have several cold air intakes in you house you can block one off if you have to put it by it.)
Start a note book that keeps every little detail you can think of in it, even incase you know the detail is wrong and fix it as soon as detected. Include an overhead room sketch in your note bood that shows windows, tank placement, approximate height off floor, doors designated as going into the rest of the house or outside, heat and AC vents and intakes. Different things work for different people, different people are comfortable with different things, and a house built in 1890 will probably require a different set up than a house built in 2008. The notes will help prevent you from second guessing yourself.
Heaven forbid it comes to it, but if something does happen to your ball you will at least be able to go back and see if some change made may be at fault. In the end you will be a better herp keeper. Once you start to get things hammered out your confidence will grow and you will start to intuitively know what has to be done. Until then your notebook will have everything written in it creating a Do and Do Not guide for yourself.