George,
I think most people thought these devices were going to detect series arcs and would also protect hazzards from appliances plugged in the outlets but this was never explained.
We only thought that because of the misinformation that was provided by the AFCI supporters. As far as the heat, I'd bet that they have never even looked at the heat when you fill the panel with AFCI breakers. They operate at a higher temperature than standard breakers as a result of the electronics. Whether this will be a problem of not, when you fill a panel with AFCI breakers remains to be seen.
Don
