Originally Posted by SouthArk370Z

I doubt that ambient temperatures, even in the hottest places in the US, are great enough to do anything to the glass itself - especially over such a short period of time. However, it could affect any coating that may be on the glass.

Without seeing the damage, my guess is that it's something on the glass (eg, wax, pollution, vandalism) or some chemical has attacked the coating on the glass.

But I'm just guessing. Take it to someone that knows auto glass and get their opinion.