If it is pressing against the glass on the cool side it might mean your ambient temps are a bit too high (just to be sure, double-check your warm hide temps also).
Give us a basic rundown of your husbandry (hot/cool/ambient side temps, hides, thermostat, etc.) and it will be easier for us to help you. If you can, also post some pics of the enclosure.
This is a nice simplified ASCII version of Pit's famous diagram![]()