two. both read 73.5. i understand these are fiddly things. I'm just not playing it right i guess. but, i have eggs to hatch so i'll keep trying.I have not used them so I cannot say for sure, but I would think just above your normal body temp as they incubate at 99.5 - 100 degrees my incubators are much larger and the elements never seem to be hot to me. Do you have a thermometer?