How cold can eggs get before they are no longer viable?

[SwedishFlower13]

I'm trying to get eggs together for someone who wants fertile hatching eggs (hoping they hatch a few for me too!) but the temps around here are still in the mid twenties to thirties in the daytime, and most of the eggs are cold by the time I find them (unless I stand out there waiting for a hen to move off a nest). How cold can they get and still hatch in 7 days or less?

 

[Kelsie2290]

http://www.brinsea.com/Articles/Advice/PowerOff.aspx Brinsea has a nice article on temps, 28.4*F seems to be the temp you don't want hatching eggs to fall below.

 

[SwedishFlower13]

*whew* thank you...now I know when eggs go into the hatchable pile!