We know. We’ve been there. Your fresh stash is reduced to one last roach. What do you do? Desperate times call for desperately searching for that one dry gram you’ve got somewhere in your underwear drawer. But before you go hunting, you should definitely give it a second thought. That’s because there’s one thing you probably haven’t considered: mold. It’s all around us—not just on our food, our drains, and our pipes, but even on our plants.

Doctors at UC Davis recently discovered five cancer patients suffering from a rare fungal infection that was traced back to a bad batch of medical marijuana—and one of the patients ended up dying as a result. As you can see, the consequences can be deadly. Check out the video above not only to understand the dangers of moldy marijuana, but for ways to keep your stash safe.