I am sure you know this but be careful! not only are they a fire hazard but acclimatize birds to temps that if the hydro(lamp) were to go could cause serious concern, ensure you have a backup plan. I am in Canada, while not the coldest part, i do know cold.
Yes and thanks. We have some of the ducks for a while already and only resort to it in the worst case (like last year).
Due to having dogs and much wildlife we go out periodically and check the grounds and animals (though the poultry is locked up at night) every couple of hours and make sure all is alright. But thanks for your concern