I'm using a styrofoam box to make an incubator. (I am completely new at this.) I have a digital kitchen thermometer and one that I bought from Menards that is a thermometer and hygrometer. I'm also using a water heater thermostat and pc fan. So my thermostat shuts the light off when my digital thermometer reads 100 degrees F. And the hygrometer/thermometer reads right around 100 as well. The digital thermometer then quickly drops temp until it's around 90. But the thermometer/hygrometer goes down a lot slower. Is this ok? Any tips? Thanks.