A woman suffered from hypothermia while rafting in a 41-degree hot weather, which is more terrible than heatstroke!

In summer, many people will choose some water activities when traveling, such as rafting. During the rafting experience, the river water wets the clothes and feels very cool, but at the same time, be careful of hypothermia.

According to headline news reports, a tourist recently suffered from acute hypothermia while rafting in a scenic spot. Why does hypothermia occur in summer? How should we deal with this situation?

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How dangerous is hypothermia?

As we all know, the human body has a temperature regulation system that, under certain external adjustments, can maintain the body's core temperature within a narrow range suitable for survival.

Hypothermia , in short, is a phenomenon in which the body's temperature regulation is unbalanced, heat production is lower than heat dissipation, resulting in a gradual loss of body heat and an inability to maintain normal body temperature.

Generally speaking, hypothermia develops in three stages: mild hypothermia, moderate hypothermia, and severe hypothermia.

In the first stage, the body begins to lose heat and the body temperature begins to drop until the core temperature drops to around 32°C-35°C. At this point, the body's first reaction is to reduce heat dissipation and speed up heat production.

Therefore, in order to speed up heat production, muscles will contract continuously, resulting in "shivering" symptoms.

In order to reduce heat dissipation, peripheral blood vessels also begin to contract, blood mainly flows into the core part, and the skin gradually becomes pale. At the same time, the exchange rate of qi and blood also decreases, and the carbon dioxide content in the blood increases. In order to mobilize the organs of the body to eliminate excess carbon dioxide, the brain is in an excited state, and the breathing and heart rate are correspondingly accelerated. However, after maintaining excitement for a period of time, the brain finds that it cannot raise the body temperature, so it begins to save energy and reduce emissions, breathing and heartbeat gradually slow down, muscles gradually stiffen, and the patient's movements become slow.

In the second stage, as heat loss continues, the core temperature drops to around 28-32°C. The patient becomes slurred, unresponsive, and in a trance.

At this point, the temperature receptors are numb and cannot transmit temperature signals to the brain. The hypothalamic temperature regulation center issues a wrong command, the peripheral blood vessels open, and the energy that was stored in the core during "energy saving and emission reduction" is dispersed to the skin and other blood vessels, making people feel "as if they are in a hot environment" for a short period of time, but in fact it results in more heat loss and a rapid drop in core temperature.

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In the third stage, the body becomes severely hypothermic, with the core temperature dropping below 28°C.

At this point, the hypothermia is already very critical. The patient is unconscious, breathing and heart rate become very slow, blood pressure drops, muscles become stiff, heart fibrillation occurs, and the patient is in danger of cardiac arrest at any time.

Therefore, the danger of hypothermia should not be underestimated.

Studies have reported that between 2000 and 2019 alone, inappropriate outdoor temperatures were associated with more than 5 million additional deaths each year, accounting for 9.43% of total deaths worldwide, of which 8.52% were caused by hypothermia . Therefore, some people also call hypothermia the "silent death."

Why does hypothermia occur in summer?

The human body itself is a pyrogen, transferring heat to the outside world anytime and anywhere. Temperature, humidity and wind are the most common factors leading to hypothermia.

Even in summer, there will be a temperature difference between morning and evening. When rafting, the river water will soak your clothes, and when blown by the wind, the evaporation of water will cause heat to be lost quickly, resulting in hypothermia, not to mention encountering severe and extreme weather.

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Why would people with hypothermia strip themselves naked?

The answer to this question also has to be attributed to the second stage of hypothermia.

As heat is lost, the body's temperature system becomes "paralyzed" and unable to transmit accurate temperature information to the brain. The hypothalamus's temperature regulation center does not receive the correct "temperature feedback", and therefore misjudges the external environment and issues the wrong command, causing the peripheral blood vessels to open. In this way, the blood used to keep the core warm flows to the periphery, giving people the illusion of fever for a short period of time.

Taking off all your clothes to "cool down" accelerates the loss of heat, causing your core temperature to drop rapidly, which speeds up the pace of death from hypothermia.

How to treat hypothermia?

So what should we do if hypothermia occurs? Here is a set of emergency procedures:

Remove from low temperature and transfer safely: If someone is found to have symptoms of hypothermia, the patient should be immediately removed from the low temperature environment and transferred to a warm, sheltered, safe environment or hospital.

Determine the degree of hypothermia and provide timely first aid: Determine the degree of hypothermia according to the patient's condition, and take appropriate first aid measures or call 120 for emergency assistance according to the severity of the symptoms.

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Keep dry and warm the core: Check the clothes of the hypothermic person and replace damp clothes as soon as possible. At the same time, use warming equipment, such as hot water bottles and heating patches, to warm the core of the hypothermic person. It should be noted that only the core should be warmed, and never rub hands and feet to warm the limbs, otherwise it will cause cold blood in the limbs to flow back to the heart, which may cause cardiac arrest.

Eat appropriately and input energy: Depending on the degree of hypothermia, let the person with hypothermia eat some high-calorie, easy-to-swallow liquid food to quickly replenish energy.

Author: Wang Xiaohuan, Ph.D., Fudan University

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