Just picked up my first HP 1200W PSU to try out. It runs VERY hot, too hot to touch. One time the fan did kick in to high speed and it cooled down but most of the time the fan is barely moving any air at all. I'm only running 350W on 120V, so it's less than half of full load (full load on 120V is 900W).
I wouldn't advise you to try to mine on a laptop if thats the case. Other than that you can try to clean the dust and try to make your room cooler. Machines can heat up very quickly and thats the "normal" beering in mind that you are mining with it which needs hell of a lot of energy and power so it heats up. It's like playing the mobile phone game that needs many of your resources and like your mobile is hot during few minutes of playing.