Interesting. A system designed to only go off with heat would render smoking bans on aircraft moot, as one could simply smoke without setting off the heat sensor- as long as they don't hold their lighter to it. Odd, I seem to recall reading a number of stories of people getting in trouble for smoking on planes. Were they holding their lighter up to the heat sensor? How about those who have set off smoke detectors by vaping? Were their stories fabrications, like those who think they are jet pilots?