HEat is always i issue with laptops. Smaller space no place for the heat to go after it comes off your CPU and Video cards. That is why the coolers are the best way to go.
Yes a overheat will cause crashes. They are the most common cause of crashes more than RAM or video card issues. Most of the time Bad RAM will cause a BSOD. A Bad GFX card will cause you not to see anything. Heat crashes it hard.
Get a cooler.