Assuming that it's well built (i.e. it comes from a major manufacturer and it's not a cheap Chinese product), that worry is completely unfounded. A modern powe

Assuming that it's well built (i.e. it comes from a major manufacturer and it's not a cheap Chinese product), that worry is completely unfounded. A modern power adapter is at its core just a transformer and a regulator. Three transformer itself is a passive device, it's the regulator that will use a bit of power that will turn into heat, but any well built one will have no risk of overheating. The heat is proportional to how much power the laptop is using, (i.e. under how much load it is on average). Modern laptops use very little power, so I'd say there is little cause for concern.