In July, a mail carrier in Phoenix, Arizona, claimed to have cooked a steak to an internal temperature of 142 degrees Fahrenheit—medium rare—on the dashboard of his delivery vehicle, which doesn’t have air conditioning.
While it’s fine for your credit card bills and other mail to get that hot, when medications are exposed to temperatures outside the range specified by manufacturers, called “temperature excursions,” they could lose their potency. For birth control pills, this could increase the chances of unplanned pregnancies.
The FDA-approved labels for common birth control formulations like Yasmin, Ortho Tri-Cyclen Lo, and Sprintec say that the pills should be stored between 68 and 77 degrees Fahrenheit, with excursions permitted up to 86 degrees. The Arizona steak got more than 50 degrees hotter than that.