The summer is here. Time to head out on vacation for fun in the sun. And, like so many people, you’re taking lots and lots of photos of yourself to share on social media. However, a harmless selfie isn’t always harmless.

“With the summer season upon us and many vacation photo-ops, you should make sure to take necessary safety precautions when you pull out your phone for a spontaneous selfie,” said Ronald S. Strony, M.D., emergency medicine physician at Geisinger Wyoming Valley Medical Center.

About 50 people have died over the last few years as a result of taking careless photos of themselves. Shockingly, more people died taking these selfies than as victims of shark attacks in 2015.

Some of the common circumstances surrounding these selfie deaths that you should be careful of include:

Heights. Some of the victims tried to snap selfies at the tops of buildings or cliffs. One 17-year-old adrenaline junkie in Russia tied one end of a rope to himself and the other to a beam at the top of a nine-story building to stage a photo that made it look like he was falling. Tragically, the rope snapped and he fell to his death. You may not have any plans to pull off a stunt like that, but don’t put yourself in a position to fall a great distance if you lose your balance.

Water. If you’re on a boat at sea, or even on a small lake, you need to be careful leaning against or over railings. There have been a number of incidents in which people leaned a little too far, fell overboard, and drowned. You need to be careful when taking selfies around water, especially if you can’t swim.

Trains. Believe it or not, it’s fairly common for people to stand in front of an oncoming train and take a selfie. Sadly, sometimes people trip, slip or can’t get out of the way in time before the train comes. We were all taught as children not to play on train tracks. That warning should be extending to not taking photos on the tracks.

Animals. You should also be careful around animals. A 32-year-old man from Spain was gored to death by a bull last year during an annual bull running festival as he turned his back to the herd to take a video.

There are several other examples of selfie deaths that started as fun photos with people handling – and then mishandling – grenades or guns. In Colorado, a plane crash that killed the pilot and his passenger was caused by an attempted mid-air selfie last year. And a few people have killed or injured themselves while taking selfies with weapons.

“While the circumstances surrounding this type of death vary, the common denominator is that the act of taking the photo distracted the victims long enough to compromise their safety in ways that cost them their lives,” said Dr. Strony. “So make sure to prioritize your safety before attempting a selfie.”