We fueled up, waited a couple of hours on weather and, as darkness fell, launched on the leg to Jacksonville, Florida. Mary and I were huddled in back, wrapped in coats, since the "full on" position of the cabin heat knob didn't make much difference. Then, somewhere north of Atlanta, in the clouds at 10,000 feet, all the radios quit. After much gesturing, switch pulling and dial tuning, Larry remembered something about the radios in this thing tending to overheat. So off went the cabin heat, and about five minutes later (what seemed like an eternity), we were back on the air … to the relief of Atlanta Center and us. There was no talk of cabin heat after that; we shivered until south of Macon, where we broke out and descended to relatively warmer temperatures.