It is an indoor/outdoor thermometer. Stick the probe right over the heat pad and put the unit on the cool side and it will give hot/cool side temp and it also shows humuidity. they sell them at home depot, lowes and walmart for around $12.00 but I cant find them on any of their web sites this is what they look like.
http://www.iaqsource.com/product.php...product=110790