Amps will get hot if the subs are at a higher rating then the amp and if you crank the amp for a long period of time. Get a radio shack fan, hook up the ground to ground and the power to the remote wire. That way, when the amp is on, the fan turns on.

Be careful, if a amp gets that hot to the touch, it will start turning off because it can't get rid of the heat fast enough and start overheating or burn out.

Past experiences.