What should my thermostat show when switching Heil furnace from winter to summer?

You are switching from heat to cool at 32 degrees? If so, I assume celsius. Most thermostats won't care what they say. It is what temp you are comfortable at. Your system won't care either. However, if you just heated the house and the burners are warm, or even the heat exchanger, then you might want to wait to allow it to naturally cool, before flipping to cool. Just to keep things from going from one temp extreme to another so nothing cracks.