I once fell asleep with a laptop on my lap that had a horrible heat sink and would basically turn itself off every half hour. My legs were crossed when I fell asleep and my heel was right up against the vent… Woke up with the laptop still on. Confused. And then PAIN. It has used my heel as a heat sink. MASSIVE burn, horrible pain, like four inch blister, still have the scar twenty years later. Had to wear flip flops for like a month shudder