i dont think i have a hygrotherm, i have something from zilla. you set the temp and the device will turn on and off the light or whatever heat soure you have plugged in. I wonder if it would work with the Repti-Fogger???
here is a picture of it.... the cord on the right gous into the wall outlet. then theres another wire that goes to two sets of male plugs...



it has a thermostat that sits in the tank. ( i have another idividual thermostat thats digital in there too)