Hydrocution: symptoms of thermal shock, what to do?

[Mise à jour le 11 juillet 2022 à 08h14] At the swimming pool as at the sea, pay attention to hydrocution ! A frequent holiday accident which corresponds to a discomfort caused by a big difference between that of the body and that of the water. The risk is particularly high when it is very hot, such as in the event of heat wave. In all cases, gradually immerse yourself in the water and do not jump into cold water after sunbathing or eating. How to react in case of hydrocution? What are the warning signs? How to avoid it? Tips

Definition: what is a hydrocution?

hydrocution is a form of drowning caused by sudden immersion in cold water. A contact that results in a decrease in the diameter of blood vessels (mechanism called “vasoconstriction“).”There are two forms of drowning: the first results from the passage of water in the airways and lungs, and the second – hydrocution or syncopal drowning – which can occur with the head above water, corresponds has a cardiocirculatory arrest on contact with water“, explains Pr Christian Virenque, emergency doctor. Hydrocution is more frequent in summer, when the temperatures are very hot, rather between noon and 4 p.m.. Children, people with a history or heart disease, and the elderly are the most vulnerable.

What are the symptoms of hydrocution?

A hydrocution is characterized by loss of consciousness or “syncope” which can lead to cardiac arrest. Some warning signs of a hydrocution can alert you:

• Itches
• Chills
• Cramps
• Hearing or visual problems
• Headaches that come on suddenly
• A sudden state of fatigue
• Paleness on the face.

• Gradually enter the water, especially if it is cold (less than 22°C). “Enter the water with caution first wetting your arms, your neck, your back, your torso and then your legs to get used to the temperature difference“, advises the specialist.
• Before entering cold water, you can also take a shower at a moderate temperature so that your body temperature drops a little.
• Do not take a cold or icy shower, you also risk hydrocution. Same thing after a sauna or hammam session.
• If you intend to swim, do not expose yourself to the sun for too long.
• Avoid bathing immediately after eating too large a meal or after consuming alcoholic beverages in excess.
• Never swim alone or in unsupervised areas.
• In the pool, use the ladder instead of jumping off the diving board.
• Avoid swimming in water below 18°C ​​for adults and below 20°C for children.
• Be even more vigilant if you have a history of heart disease or are over 40 years old.

Contrary to popular belief, digestion does not promote the risk of hydrocution. However, it is better to avoid bathing directly after eating and wait about 3 hours before taking a dip. Indeed, the after meal generally corresponds to the hottest moment of the day. It is prolonged exposure to the sun (between 12 p.m. and 4 p.m.) that increases the risk of hydrocution. Likewise, iAvoid drinking alcohol before swimmingbecause it increases the risk of loss of consciousness.

A cold shower increases the risk of hydrocution. Indeed, water that is too cold accelerates the rhythm of the heart and causes sudden syncope. Similarly, you should not take a cold shower after a sauna. But it is better to take a lukewarm shower first, then lower the temperature gradually for the body temperature to drop.

What causes hydrocution?

After a large meal, prolonged exposure to the sun or excessive alcohol consumption, the body temperature increases. Can then happen then differential thermal shock which causes cardiac syncope, on contact with water. A hydrocution is therefore due to the difference in temperature between an emerged body (which is generally around 37°C) and cooler water. “Of course, the greater the temperature difference between the body and the water, the greater the risk of hydrocution.“, specifies our interlocutor.

What to do in case of hydrocution?

If you experience one or more of the signs mentioned above, it is advisable to get out of the water immediately. If you see someone who appears to be the victim of a hydrocution on the beach or at the pool, here’s what to do:

→ If the hydrocuted person is conscious, get her out or help her out of the water as quickly as possible and lay her down on the ground. Immediately notify the lifeguards if there are any on site or call the fire department, Samu or 112. By the time they arrive, try to warm her up and dry her with a towel, and reassure -the. Make sure you have fewer people around the victim so that they have as much air as possible.

→ If the hydrocuted person is unconscious, get it out of the water and call for help. Clear her airway and check that she is breathing.

After the emergency services have left, it is advisable to monitor the person in the hours that follow.

• If she is breathing, Tilt his head back very gently while maintaining spinal alignment, put him in the lateral safety position (PLS) and wait for help to arrive.

• If she is not breathing, give him mouth-to-mouth if you know the maneuver or ask someone to do it. If you do not perceive any sign of life (the person no longer speaks, no longer responds and no longer breathes), practice cardiac massage only if you know how to do it or call a lifeguard, a sea rescuer or any person able to do so. If no one is trained in CPR, wait for help.

As soon as they arrive, the emergency services will have to make the difference between a simple malaise, hypoglycemia and hydrocution. Depending on the time of the incident, the symptoms and the state of the victim, they look for signs of respiratory activity, note or not the cardiac arrest and pose or not the diagnosis of hydrocution. After the observation of a cardiac arrest, they then very little time to resuscitate her. In the absence of a pulse, they perform heart massage or pose a defibrillator, a device that analyzes the heart rate of the victim, before administering an electric shock if necessary. “The chances of survival increase by approximately 70% if resuscitation and defibrillation are done in the first three minutes following the accident“, specifies the emergency doctor. After the emergency services left, it is advisable to monitor the person in the hours following the accident to check the evolution of their symptoms and their condition.

What to do in case of hydrocution in the child or baby?

React in exactly the same way if a child or baby is the victim of a hydrocution. The only differences: you have to make a “mouth-to-mouth-to-nose” if the baby is less than a year old and a “classic mouth-to-mouth” after 1 year. If no cardiac activity is identified, cardiac massage should be performed:

• Before the age of one year, cardiac massage is done by placing the thumbs in the middle of the chest. Perform compressions (between 100 and 120 compressions per minute) making sure to press the chest down on a third of its thickness.
• Between 1 and 8 years oldplace the heel of the hand in the center of the chest and perform compressions (between 100 and 120 compressions per minute) making sure to press the chest down on a third of its thickness.

Can you die from hydrocution?

The greater the thermal shock, the more the person is at risk of faint which may be accompanied by a reflex stoppage of breathing and cerebral circulation. By losing consciousness, the person can thus sink and drown by asphyxiation. That’s what we call “drowning by hydrocution”hence the importance of reacting quickly and well!

Thanks to Professor Christian Virenque, emergency doctor.