VERY Hot!
Well, I always grab by the plastic head, but I could still feel the heat coming off of it. It was really really hot! But it gets lots of air across it up in the air, I would think. It's just from pulling it to packing it away that I let them cool off for a good 30 minutes.I ask because I heated one of my batteries up pretty good on a hot day (I'm 50 miles west of Las Vegas NV) and I could hardly hold it, it was so hot. May have hurt it so I'm keeping my eye on it.