Well you have two different kinds of temperatures, ambient temp and floor temp. In my tubs I have the hot side of the tub at 90-91 degrees floor temp (read with infrared thermometer) The floor temp in the front is around 80 and the ambient temp (air temp) in the tub is 85deg. how are you taking your temp readings? what type of cage? and to answer your question No 100 degrees is not good so in the mean time move the hide off the uth.