LDs are different from CDs and DVDs. LDs are glued together and heat does kill glue. CD/DVD is pretty much all plastic and metal and is essentially welded together with more plastic. They are quite heat resistant. You may need to be more careful with recordable CDs and DVDs since they have more ingredients, I'm not sure.

That said, there is some point when direct sunlight can probably destroy a CD, use a little caution.