Ohhh.. at about 450 degrees ! It bubbles at about 500 degrees ! A very valuble lesson has been learned here. My 15yr old has learned not to put his i-phone on the woodstove while firing it up while mom is at work. My ex has learned that he should have given me the $500 for wood instead of spoiling the child with an i-phone. Hate to say "I told ya so" !