I'm looking for any tricks to keep the air in my snake tank warm, preferably without heating the entire room.

It is a glass tank (i know plastic is better for this, but that is not really an option at this point since i already have spent the money on a glass tank.

I have an UTH that is on all the time, and a heat lamp that i use when the temps get too low, but it butchers the humidity.

I'm thinking of getting some kind of insulation to put on the back and sides. Does anyone have any other tricks or will i have to heat the entire room?

Thanks in advance.