Polar bear swims are not for the feint of heart, and even the most stalwart (and cold-tolerant) plunger can employ a few strategies to make the swim a success.Come wintertime, polar plunges are sponsored by various organizations. Such events may serve as fundraisers for club operations or to help needy individuals, while others may simply be efforts to fend off cabin fever.

While no one can say for sure who originated the polar plunge, the first recorded Polar Bear Swim took place in Boston in 1904. In Canada and the Netherlands, it has become tradition to host plunges on New Year’s Day. Even people in the southern hemisphere participate, with plunges off the coast of New Zealand and Antarctica in June. In the United Kingdom, a “Loony Dook” takes place in Scotland, with several thousand people attending the event and taking the plunge after New Year’s Eve celebrations. The largest plunge in the United States is the Plungapalooza in Maryland, which includes 12,000 swimmers, all of whom are there to raise funds for the Special Olympics.

Polar bear swims are not for the feint of heart, and even the most stalwart (and cold-tolerant) plunger can employ a few strategies to make the swim a success.

• Prepare in advance. Build up your cold tolerance in the bathtub or shower. Cold water may cause some people to hyperventilate. Acclimating to the sensation can make it less shocking when it’s time to get in the water.

• Exercise caution if you have a heart condition. Experts in medicine at Mount Sinai Medical School say that, following cold shock, the body will do something called a diving reflex. This means constricting blood vessels to direct more blood flow to the heart and brain, which causes an increased cardiac workload.

• Walk slowly into the water. Rather than running and diving in, slow enter the water to acclimate your body to the cold and mitigate some of the shock.

• Make it a brief stint. Only stay in the water for a few minutes. Doctors say that cold water incapacitation can begin within five minutes of entering the water. Hypothermia requires being immersed for 30 minutes or more to set in.

• Bring along warm clothes. You’ll need to warm up quickly after the plunge. A terry cloth bath robe, thick wool socks, heavy sweater, and a hat can help restore body heat.

• Avoid alcoholic beverages. Alcohol can give off a false feeling of warmth and heat in the body. Alcohol dilates blood vessels, increasing blood flow to the limbs at the expense of the core. It also may interrupt the body’s natural shivering response. Warming up with some scotch is not advisable before or after the plunge.

If health ailments do not preclude a person from plunging, it can be an exciting way to spend a few wet minutes.