P7 was designed with tactical ops in mind. In a pistol fight you are very unlikely to fire more then couple of magazines. If you need more, you should have brought a long gun!
The heating problem is not really a problem, but design peculiarity.
In order to house the gas delay system directly inside the dust cover, they had to divert the gasses stright fron the chamber down, right where your trigger finger is positioned. There is no way around it. The have minimized the burning issue when M8 model came out (plastic shield), but unless you really place a ceramic (or any other REAL theroinsulator) underneth this port, you can not do anything. Personally I bring more then one gun to the range, so I let it cool off.