Yes, they can overheat and burn the laptop, if the cooling system is not working well and it gets very hot (when they put on a movie or play an intensive video game for example) then electronics stop being stable. The best way of avoiding this is to have proper ventilation of the laptop by keeping it open on a ventilated surface, but also always keeping it cool – don’t put ice cubes in your lap, because that just boils the water out of them and makes everything hotter. You can also use a stand with a fan that sucks air from underneath the laptop case.