If it's a major concern and you don't already have them, you might also consider getting black rims.
According to Kirchhof's Laws of Thermodynamics, dark surfaces are more apt at absorbing and radiating heat away. The black rims will of course feel hotter to the touch, but that's because they're doing their job.
It's the same reason the bottom of the space shuttle and the backs of most refrigerators are black.