Will extreme temperatures damage CDs?

United States
December 9, 2008 2:28am CST
i have a cd player in my car and of course i leave cds in there to play and i worry that they are gonna get screwed up.. i have most if not all on back up on my mp3 player but some are starting to skip and i dont know if its dirt or if the cold temperatures outside are screwing them up.. i figured the heat would have been worse so when they did fine all summer i thought i was in the clear.. will the different temperatures outside affect the cds in my car?? which is more harmful cold or heat?