Using a Laser when it's cold

I keep my 5mW in the car a lot.  It's dark when I drive to work, so naturally, I play around with it.  I usually sit it under my leg in the seat for a few minutes to let it warm up, because it's COLD after sitting out overnight.  

My question is: is it bad for the laser to use it cold like that?  Is there a good cut-off temperature that it should not be used if it's below XX degrees?

(and no, I don't turn it on around traffic, etc.)  


Thanks,

Usually the only lasers that react badly from being too cold are DPSS lasers (green, blue, yellow). Cold doesn't harm them permanently, it just causes them to dim or stop working until they warm up. Diode lasers (red, blu-ray) aren't really adversely affected by cold unless it's well below 0F if then. i wouldn't worry much about permanently damaging your laser from the cold. Too much heat is far worse.

Beware that a lot IR may come out when its so cold green output has been reduced to zero. The laser will be fine though.