tajoch,
Can you give us more information? What type of wire is it, what are the loads on the circuits?
Assuming it is THHN and that you have a neutral per circuit your capacity would be down to 13.5 amps (45% of 30A) if you are anywhere near that load that explains where the heat is coming from. If you can change these wires to #10s or remove half of them you should be Ok.
Bill
