Most of the time, the rest of our bodies are covered, with the possible exception of our hands which together only make up about four per cent of our surface area , so we feel cold, because our head is cold compared to the rest of our insulated body. If a person had to expose another part of their body — for example, their abdomen, which also makes up about 10 per cent of an average adult body — then they would lose as much heat through that as their exposed head.
It has more to do with the relative size of the head to the body. They also have a faster rate of heat loss than adults, generally speaking. Due to their large head relative to their body, they also need their heads covered to prevent significant heat loss. Old age — in the elderly, the ability to notice changes in temperature is impaired due to the loss of nerve endings to the skin.
They also have less fat, which has an insulating function, and a lower metabolic rate, and so generate less heat themself. Social factors also play a part, as the elderly are more likely to be reluctant to use heating for economic reasons, and they may be socially isolated so can be alone for long periods of time with no one noticing as they deteriorate. Dementia or immobilising illness — anybody who is unable to look after themselves independently, either physically or cognitively, is at risk of hypothermia.
People with dementia can be particularly at risk if they wander off in cold conditions without having protected themselves with appropriate clothing first. Alcohol and other drugs — alcohol makes people feel cosy because it relaxes the blood vessels, allowing more blood to flow near the skin, providing a flushed appearance and a warm sensation. This also puts people who are drunk at significant risk of hypothermia if they are outside in cold weather, as this increases the rate of heat loss.
It also slows down the metabolism, so slows down internal heat generation. Alcohol also impairs judgement, so the person is less likely to recognise the environment and their own physical condition, and less likely to take protective measures against heat loss. This is also a concern with any other mind-altering substance.
Water immersion — people who spend any time immersed in water that is colder than body temperature will suffer significant heat loss.
The other person at risk is anyone who may have been in wet clothes for a prolonged period of time, either due to incontinence or sweating. Under this temperature, a person will be very cold to touch, unresponsive, rigid, not breathing, have no pulse, and their pupils will be fixed they will not respond to light changes.
They will appear to be dead, but they may not be. First aid for severe hypothermia First aid steps for severe hypothermia include: In an emergency, call triple zero If they have severe hypothermia, their breathing may become dangerously slow or shallow, or they may cease breathing. Begin cardiopulmonary resuscitation CPR immediately if the person shows no signs of life — if they are not breathing normally, are unconscious or unresponsive, or not moving.
Never assume a person is dead. A person with severe hypothermia may only take one breath per minute, with a heart rate of less than 20 beats per minute. Always assume they are alive.
First aid for all cases of hypothermia The first aid tips that apply to all stages of hypothermia include: The first step in all cases of hypothermia is to prevent any further heat loss. This is done by removing the four ways that heat loss occurs mentioned earlier, including: Conduction — remove the person from a cold surface if possible.
Ideally, place them onto a warm surface, or at least a dry one that will prevent further heat loss. Convection — remove the person from a windy or wet environment. Covering with blankets is good, but the aim must be to get them to shelter.
Radiation — Cover as much of the person as possible to avoid radiant heat loss. Particularly cover the head of a younger child. Evaporation — wet and sweaty people will suffer evaporative heat loss. Dry skin where possible and remove wet clothing as soon as practicable. Keep them still because, particularly below 32 o C, they risk a cardiac arrest. Move the person out of the cold — if this is not possible, protect them from wind, cover their head and insulate their body from the cold ground.
If the person is moderately or severely hypothermic, move them as gently as possible. Below approximately 30 o C the heart is very vulnerable and there are case studies of simple movements like rolling the person over prompting a cardiac arrest.
Remove wet clothing — replace with a dry covering, preferably warm. Try to warm the person — do not use hot water immersion. Make sure that the person is dry. Normal body temperature is around When your body temperature drops, your heart, nervous system and other organs can't work normally. Left untreated, hypothermia can lead to complete failure of your heart and respiratory system and eventually to death. Hypothermia is often caused by exposure to cold weather or immersion in cold water.
Primary treatments for hypothermia are methods to warm the body back to a normal temperature. Shivering is likely the first thing you'll notice as the temperature starts to drop because it's your body's automatic defense against cold temperature — an attempt to warm itself.
Someone with hypothermia usually isn't aware of his or her condition because the symptoms often begin gradually. Also, the confused thinking associated with hypothermia prevents self-awareness.
The confused thinking can also lead to risk-taking behavior. While you wait for emergency help to arrive, gently move the person inside if possible. Jarring movements can trigger dangerous irregular heartbeats. Carefully remove his or her wet clothing, replacing it with warm, dry coats or blankets. Hypothermia occurs when your body loses heat faster than it produces it.
The most common causes of hypothermia are exposure to cold-weather conditions or cold water. But prolonged exposure to any environment colder than your body can lead to hypothermia if you aren't dressed appropriately or can't control the conditions. Alcohol and drug use.
Alcohol may make your body feel warm inside, but it causes your blood vessels to expand, resulting in more rapid heat loss from the surface of your skin. The body's natural shivering response is diminished in people who've been drinking alcohol.
In addition, the use of alcohol or recreational drugs can affect your judgment about the need to get inside or wear warm clothes in cold-weather conditions. If a person is intoxicated and passes out in cold weather, he or she is likely to develop hypothermia. As winter drags on and temperatures drop way down, your risk of cold-related injury like frostbite can go way up.
Sanj Kakar Mayo Clinic Orthopedic hand and wrist surgeon says frostbite is more common than many people think. Kakar explains. If the windchill drops below negative 15 degrees Fahrenheit, not unheard of in the northern half of the U. It is important to remember that cold water shock can occur throughout the year, even during warm summer months when water temperatures can remain lower than outside air temperatures.
Have a question? Ask or enter a search term. Select Your Country. Hypothermia Hypothermia is a drop in core body temperature, caused by prolonged exposure to abnormally low temperatures, such as immersion into cold water.
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