[Deaf Smith]

40 degrees is not a freeze.

[PJ-Comix]

40 degrees is enough to put the iguanas into hibernation mode. If it lasts for only a day or two, the warming suns rays will bring them back to life from near zombie status. However, if 40 or below temperatures last for several days, it is enough to kill the iguanas.

Oh, and for folks in South Florida, below 40 degree weather is considered a "freeze" although technically it is not. People down here break out heavy winter clothing even if the temperature drops to only about 60 degrees.

[VTenigma]

No kidding. At certain times of the year 40f is t-shirt weather around here.