I keep a big, hardcover book next to my couch for when I want to edit photos in Lightroom with the computer on my lap. Without that tome to protect my legs, my laptop slowly roasts my thighs as if they’re salty, delicious slabs of meat at a South African shisanyama. Laptops get hot when you subject them to resource-intensive activities. That’s just a way of life—and why they generally need fans to stay cool. But when Apple announced its new MacBook Air last week, the company promised the new M1 chip would keep the whole machine cool even without a built-in fan to funnel hot air away from the delicate electronics.