Also, sometimes its not how low the temperature goes but how long it stays there and what the following daytime temperature is. So if BigBill's temperatures hit 25 but stayed there for only 30 minutes or so and then the daytime temps were in the 40's or 50's, there may be no damage at all. If the 26 temp lasted a couple hours and the next day high was only 30, the chance of damage would be much greater. And, as BigBIll pointed out, it was two nights, not two weeks.