Today marks the official first day of summer, a time typically filled with lots of outdoor activities including swimming, going to the beach, backyard barbeques, and more.

It’s not always fun and games in these months though, as some health concerns arise this time of year. WebMD has compiled a list of the seven most common summer health hazards. Dehydration is third on the list.

Mayo Clinic defines dehydration as “losing more fluid than you take in, and your body doesn't have enough water and other fluids to carry out its normal functions.” It is most prevalent in the summer months because of the heat, more time spent outdoors, and increased perspiration.

Symptoms can include lightheadedness and nausea, but can be usually be easily remedied by drinking more fluids, preferably water, and cooling off in the shade or air conditioning.

The most severe form of dehydration is heat stroke, which is when the body temperature rises to dangerously high temperatures, while the body stops sweating. People suffering from heat stroke are at risk of blacking out, experiencing hallucinations, and having seizures. If left untreated, it can lead to heat cramps and heat exhaustion.

Treatment for heat stroke requires getting inside, cooling off with ice packs and moistened cloths, and replenishing water in the body with plenty of fluids. If symptoms subsist, a trip to the emergency room may be necessary to receive intravenous fluids.

Prevention of dehydration and heat stroke is key. Try to avoid spending excessive amounts of time outside during the strongest heat of the day; instead enjoy the outdoors in the morning or late afternoon. When outside, be sure to monitor fluid intake and alternate time in the sun with time in the shade.

Enjoy the outdoors this summer, but do so safely!