Question for Betty.
I accidently left my birth control pills in my car for two weeks in freezing weather.  I know that heat can effect the way birth control works.  Can the cold?
Betty's Answer.
This is a really great question, as we do have freezing weather for about 7 months of the year in Anchorage.  Unfortunately, I could not find a definite answer for you.  Pharmaceutical manufacturers recommend that most of their products be stored at a controlled room temperature of 68 to 77 degrees. This is the range in which manufacturers guarantee product integrity.  Do our homes always remain between 68 and 77 degrees?  Most definitely not. 
Local Anchorage pharmacists advised me that manufacturers usually state that it is okay to have their pill form products below freezing for 24 to 48 hours, but they will not guarantee product integrity past that time, as they have not been tested after prolonged freezing.

Call your health care provider for advise.  You may want to ask for replacement pills, or if you decide to take these pills, it may be prudent to use condoms in case the efficacy is reduced.  

With travel it also would be prudent to carry medications onto the airplane when you travel, as baggage holds are not controlled for temperature, and baggage may be lost.