I don't think I need a thermometer to tell me how the insert is burning but I got a cheap ($5) digital temp. gauge with a thermocouple. I put the thermocouple in a magnet and put that on the top of the insert in whe hole where the air came out. Judging by the smell, I don't think the thermocouple is going to last. It's Celsius. I've read a high of about 453 F so far. The eBay link is here: http://www.ebay.com/itm/280929959185?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 It was cheaper when I got it.