Is it ok to keep them in your car's glove box? By this time of year it gets really hot in there during the day, and the package says to keep them in cool dry place (until they're being used ). I'm wondering if it is risky to use one that's been in a hot car for a few days, does heat degrade the latex? Maybe it's just a CYA thing on the part of the manufacturer, but I guess I'm paranoid!