try putting that mister on a timer so that it doesn't go off so often. it will be 90 right after it goes on, but then should taper down pretty quickly to the 50's. Like a previous author said, too high humidity leads to bacteria and other problems. honestly, i would suggest getting rid of it altogether and trying to use a larger water dish on the warm side of the enclosure combined with restricting the airflow out the top.

JonV