If your laptop is overheating, there could be two causes. If the fans on your computer are running constantly but your laptop is still overheating, your air vents may be clogged. This means the air isn't circulating through the laptop. This just takes some cleaning of the air vents located on the side and it should stop overheating. A more serious issue could be that the fans are not working properly. If you do not feel hot air blowing out of the vents at all or you do not hear the fans running, the fan is either not connected properly within or it is going to need to be replaced. Here's a link to a troubleshooting guide that can help you further: Laptop Overheating