Wire mesh in the door can help, however, the temperature isode the cabinet will still rise. The best thig to do is to incorporate some kind of ventillation system into the cabinet itself. We use products from a company called "Active Thermal Mamagement".
Take a look at their site at www.activethermal.com and you'll get some great ideas. Alot of them can be put together through a store like "The Source" or any computer store. At a minimum, you can install a computer fan into the back of the cabinet and plug it in on a timer or a reverse thermostat (It comes on when it gets too hot)
Good Luck!