This morning it was 64 by the outside temp reading on my Pacifica. I have no idea if that was realistically close or not, but for us it was a bit chilly since a few weeks ago, it was in the 90's this early in the morning. Anyway, I turned on the driver side seat heater and it showed as being on hi and it did start to feel warm. I did the same with the passenger side, and my wife said it was warming up. When we stopped, I left them on to see what would happen, and sure enough, they were turned off when we started up again. That's good, since that's what all my other vehicles that had heated seats did and I don't mind turning them back on if I need to. So, the outside temp reading has no bearing on whether the seat heaters go on or not, for us that's good since it rarely gets below 40 degrees, maybe a half-dozen times in the winter, but anything under 60 degrees is getting cold around here.