This is just a little peeve of mine but just because our body temp is 98.6 doesn't mean your ENTIRE body is at 98.6, it represents the core body temp. Your appendages can be 10-15* cooler. So it isn't really accurate to guess the heat of something with you hands.

I would just set your thermostat at like 95* right now and wait until you get the heat gun, then you can fiddle with it more.