What is a hydrocution?

Is hydrocution possible in his swimming pool?

Hydrocution is a violent thermal shock for the swimmer. What are the factors that trigger hydrocution? How to avoid it? What are the risks for the body and how to react to a hydrocution?

What causes hydrocution?

Hydrocution can “hit” a bather when the temperature difference between the body and the water is very large, such as, for example, long exposure to the sun followed by a direct dip in the pool to cool off! The shock is all the greater because in water the body cools 25 times faster than in air. The body must simultaneously fight against heat and against cold. Sudden entry into the water immediately causes the body to react, this can have dramatic consequences and cause death.

Hydrocution is a frequent cause of drowning, it is thermal shock whose consequences on the body cause the most drowning. Several hundred cases are recorded each year.

Hydrocution: what are the risks for the body?

The difference between body temperature related to high ambient heat and rather cool water has more or less serious, dangerous consequences, it is a real stress for the human body.

It ranges from simple chills, from itching to muscle pain, cramps or hearing and visual disturbances. Nothing serious? Except that the cramps can prevent reaching the edge of the pool.

The sudden difference in temperature causes the retraction of the veins and the drop in blood pressure. The more the violence of the shock is felt, the more there is a risk of fainting, heart attack, infarction or stroke which leads to a high risk of drowning.

The populations most at risk are the elderly and those with heart problems. They must therefore be particularly attentive to the gestures of adaptation.

How to avoid a hydrocution?

What are the steps to take to avoid hydrocution?

A gradual entry allows the body to get used to the freshness of the water, the change in temperature and limits the risk of hydrocution. You have to take the time to get wet, the ankles, the stomach, the chest, to spray the arms, the neck, the face, the back... Thus the body can adapt gently, to the new temperature conditions which it are imposed. It is better to take a shower or to descend slowly into the pool using the steps or the ladder rather than to dive.

To avoid the risk of hydrocution, it is also advisable not to bathe after consuming too much alcohol and/or after a meal, especially if it has been copious.

Finally, to complete the recommendations, it is advisable not to swim alone. Indeed, if a hydrocution occurs, the people present can intervene and avoid drowning. Certainly, the spontaneous effect of the bomb is undermined! But this adaptation time is necessary and perhaps life-saving.

How to react to a hydrocution?

When the symptoms of hydrocution appear, that you are conscious, get out of the water, do not insist. Sit down and cover yourself with a towel, bathrobe…this is to raise the body temperature.

If you witness a hydrocution, help the person out of the water, lay it on the ground, dry it, cover it to warm it. If victim is unconscious, check breathing. If she is breathing, gently tilt her head back and if you know the gestures, place her in a safe lateral position. If the victim is not breathing, a cardiac massage must be done by a person trained in this practice.

In all cases, and as soon as the first aid measures have been performed, notify the emergency services as soon as possible (15, 18 or 112).


Entering the water slowly is a simple, non-binding prevention, the adaptation period should not be neglected or too short to accustom the body to the deviations temperature and avoid any risk of hydrocution. Never mind, nothing prevents once wet, to make a beautiful bomb!

Hydrocution is the deadliest thermal shock. But there are other equally fatal thermal shocks. Get to know what is hypothermia and what is hyperthermia so you can respond in the best way if you are a victim or witness to it.