Cold water makes you stiff, and falling into the water, especially without protective equipment, can be fatal very quickly. In the prevention of hypothermia, the primary task is to be aware of the dangers and avoid unnecessary risks. This article introduces hypothermia and its development in water with lifeguard class near me.
Hypothermia refers to the drop in normal body temperature and the resulting changes in the body. If the cooling cannot be stopped, cold death will follow. Almost 100 people die from accidental hypothermia in Finland every year.
Several different reasons predispose a person to hypothermia. Usually, the victim is a heavily intoxicated, drunk or drug overdosed person who has been left in the cold outdoors. A less common victim is a hiker or a lost child. In addition to hypothermia, a person exposed to water is at risk of cold shock. When moving on water, boaters, fishermen and children, as well as those moving on ice in winter, are especially exposed to hypothermia. The strongest and fastest cooling takes place in cold water.
- In cool water, the risk of hypothermia is close without the right protective equipment. The cooler the water, the faster hypothermia develops. All water users are at risk of acute hypothermia both in winter and summer. Many of those who fall into the water die before help arrives, says Niko Nieminen, communication specialist of the Finnish Swimming Teaching and Lifesaving Association (SUH).
The probability of hypothermia increases the longer a person is dependent on water
- Acute hypothermia is a danger after a person accidentally falls into cold water. When exposed to cold water, a person experiences physiological stress responses, the nature of which depends not only on the temperature of the water, but also on how long the person is in the water (duration of immersion). In terms of survival, the first moments in the water are the most critical.
In acute hypothermia, where a person has had to rely on water, the exposure time is usually between 30 minutes and 6 hours, depending on the prevailing conditions and the individual characteristics of the person.
- Hypothermia is classified as mild (34-35°C), moderate (30-34°C) and severe (<30°C). As the body temperature drops, the person develops symptoms of hypothermia, the occurrence of which depends on the degree of hypothermia.
- The cold affects most of the body systems and their functioning. Normal body functions begin to deteriorate when the temperature of the internal organs drops below 36°C. The time strategy for someone who accidentally falls into cold water can be divided into cold shock, short-term and long-term immersion.
Cold shock (0-3 min with water)
When a person unexpectedly falls into cold water, the sudden irritation of the cold receptors of the skin and peripheral parts triggers a series of responses collectively known as cold shock. The body works reflexively for the first few seconds. The victim holds his breath for a moment, followed by hyperventilation. Panic and the feeling of fear of escape make the victim gasp for breath, and the victim easily draws water into his lungs. As a result of hyperventilation, the carbon dioxide concentration in the blood decreases, which lowers the level of consciousness. A person caught in water usually has difficulty keeping his airway above the surface of the water, which increases the probability of drowning.
At the same time as the breathing changes, the heart rate increases, the cardiac output increases and the secretion of stress hormones increases. In response to the rapid drop in skin temperature, peripheral blood circulation contracts, raising arterial pressure, which increases the load on the heart and pulmonary circulation. The result can be ventricular fibrillation, arrhythmias, fluid accumulation in the lungs and cardiac arrest.
- In Finland, several people die of cold shock every year in water accidents. There are no reliable statistics, as cold shock deaths are usually recorded as drowning. Regular exposure to cold water mitigates shock responses. Those who move a lot in the water should get used to exposure to cold water by taking cold showers or swimming regularly in cold water, says Nieminen.
Short-term immersion (3-30 min under water)
As the temperature drops, the body increases heat production with the help of metabolism and muscle tremors. Vague early symptoms include fatigue, slurred speech, hunger, malaise, speechlessness, moodiness and confusion. Old age, physical and mental condition, dehydration, fatigue, alcohol and illnesses predispose to cooling.
Swimming may be impossible at the beginning of an accidental immersion during the hyperventilation phase. The ability to calm down and balance breathing enables swimming movements. However, swimming in cold water is slow, because the swimming position is upright and the swimming movements are restless.
As the cooling progresses, the control ability of the central nervous system weakens, making it difficult to coordinate swimming movements. Gradually, the gliding phase of the swim becomes shorter and eventually it is not there. Rescuing yourself from the water becomes more difficult, as the motor performance weakens, strength decreases and brain activity slows down. Getting on a ferry, boat, ice or beach may even be impossible at this stage.
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