The probe and wire are metal and dont burn, the thermometer boby is plastic and can melt. I've used it on a barbecue by using the magnetic back on the body to attach it to a leg of the barbecue, away from the heat, with good effect. You wouldn't be able to stick it directly to the drum near the coals as you'd probably melt it.
I agree with A Bowles reply, though you would need to position the probe so it measures the temperature where the food is positioned rather than in the charcoal - maybe a separate magnet to fix the probe to the grill?
BBQed thermometers are a bit tough on the teeth!! sorry for the humour, but yes stick the end of the probe in the meat wait for the reading to settle and hey presto there is your half cooked salmonella-laden sausage! Recommended temp is 65deg but I ALWAYS, ALWAYS go to 85deg to make sure. Keep the whole instrument away from the action of the cooking whhen not in use to keep it safe. so happy bbq'ing. The product is an excellent tool particularly for checking the real temperature of an oven as the cord fits snugly between the door and seal with no loss of heat and temp can be read in comfort.