75F!!! Id melt! LOL! I like my house at 68, or cooler. My snake room heater stays set at 75-77 depending on the time of year. Being set there the RHPs are good in my cages. I have ProProduct panels in my large cages. I called and discussed my cages with them and bought what they suggested.
I think we found the common thing that makes them work and that's having a warmer room. I don't know how you deal with 75 in your house. My farther-in-law is like you and I just cant do it.