Your problem is most likely NOT the amplifier.
If you had the gains on the amp up to high then after a while the speakers could blow.
Now, if the speakers are blown then chances are the resistance on them is no longer the normal 3.5-4.0 ohms but could be up extremely high. If the amp is trying to push that much current through say an abnormal 16 ohm load (from a blown speaker) then it's going to heat up because it's working a hell of a lot harder. The amp is going into protect mode because it is getting so hot from this resistance.
Replace the speakers. It doesn't matter what the power handling on the speakers is, if you're gains are up to high and you're sending a clipped signal to the speakers, they will blow eventually.