Prolonged idling (read: stationairy heat) is what kills most modules.
At idle there's plenty of dwell and a lot of power is going through the module, which heats up fast this way. Especially if there isn't any/much engine bay air movement.
I had a module fail years ago in a '86 Opel after getting stuck mostly stationairy traffic jam. The moment the traffic jam slowly dissolved the module crapped out. Overheated.
Had similar happen last year when I ran 4-pin module in my Dart.
Ended up in a big very slow moving traffic jam on the highway lasting for 20orso minutes. Finally got to my off-ramp and half a mile later the module craps out.
I'm currently running a 7-pin module with digital ignition, where I can control the coil's dwell-time better, so less energy goes through the module at idle, thus not heating it up that much.
