As Cape Cod enters jellyfish season, beachgoers are experiencing painful stings from moon jellies, lion's mane, and Atlantic bay nettles.
Jellyfish researchers say if you get stung, use heat for relief.
When heading to the beach, be on the lookout for purple flags, which are posted by lifeguards when there are an above-average number of jellyfish in the area.
Typically, jellyfish season runs through August, but can extend into September.
(Photo by Will VASSILOPOULOS / AFP via Getty Images)