During a challenge, thermostat set temperatures are gradually lowered by a few degrees below the regular set temperature.
If you choose the preheat option, the set temperature of your thermostats will be gradually increased two hours before the challenge. You’ll accumulate heat in your rooms and be more comfortable.
The hour following the challenge is the return-to-normal period, in which your thermostats gradually go back to their regular set temperature.
You don’t have to lift a finger: it’s all programmed for you!