I searched all over and can't find the answer to this. I got the temperature just right in my homemade Styrofoam incubator, but humidity was low. So I added more water, and now the temperature went down.
I've been able to find all sorts of wonderful information on the forum, but not specifically the answer to this. Am I going to have to fiddle with the temperature every time I add water? (Thankfully I have a digital controller coming this week, but until it arrives...)