The Warning Signs of Hypothermia: Symptoms and Prevention
Medically reviewed and edited by Each year, the U.S. reports between 700 to 1,500 cases of hypothermia, highlighting the importance of cold weather safety and awareness.
Since 1979, America has recorded more than 19,000 deaths due to cold-related causes – but with the right information, you can make responsible choices and protect yourself and others from hypothermia.
What is Hypothermia?
Hypothermia occurs when the body’s temperature drops below 95℉, impairing essential functions. It's typically caused by prolonged exposure to cold, which leads to excessive heat loss.
Cold exposure requires us to tap into our survival instincts to preserve body heat by wearing warm clothing and seeking shelter.
The body's built-in cold defenses help prevent significant temperature drops and stabilize temperature despite external cold conditions.
Body heat preservation mechanisms against hypothermia
The body uses the following protective measures to avoid heat loss in cold temperatures and prevent hypothermia:
Skin: This serves as a barrier against heat loss.
Shivering: Our muscle fibers contract quickly, burning energy and causing heat to be produced.
Peripheral vasoconstriction: Contraction of small blood vessels in the skin reduces blood flow to the surface, minimizing heat loss to the environment.
Piloerection: Commonly referred to as “goosebumps,” hair standing on end creates an insulating air layer, reducing heat loss.
Thyroid hormone increase: This boosts metabolism and heat production to maintain warmth.
If the body's defenses can't shield you from the cold, hypothermia may develop, meaning a core temperature of below 95℉. Core temperature measures the warmth of internal organs, not the skin's surface.
To measure core temperature accurately, thermometers are used in various internal locations – such as the rectum, underarms, tongue, nose, esophagus, bladder, or ears – noting that measurements under the tongue and arms are often less reliable.
Measuring skin temperature is not recommended for these assessments as it can be easily influenced by external cold sources and reduced blood flow in cold conditions.
Hypothermia is categorized by severity as follows:
Mild: 90-95℉
Moderate: 82-90℉
Severe/profound: Below 82℉
What are the Causes of Hypothermia?
Hypothermia occurs when there is excessive heat loss or when the body's ability to produce or maintain heat is compromised.
It's characterized by a drop in core body temperature. Key risk factors are discussed below.
Controllable hypothermia risk factors
Wet clothing: Acting as a conductor to colder temperatures, wet clothing accelerates the loss of heat from the body and causes the core body temperature to fall.
Alcohol use: This leads to vasodilation, allowing more heat to escape from the body.
Malnutrition: A lack of body fat diminishes insulation against cold, and insufficient nutrition compromises the body's ability to produce heat, leading to a quicker fall in body temperature. This may also be an uncontrollable risk factor if it occurs due to poverty, which we’ll discuss below.
Hiking at high altitudes: This can expose individuals to colder environments where the risk of wet clothing and contact with cold ground is higher, leading to a rapid drop in body temperature.
Uncontrollable hypothermia risk factors
Exposure to cold environments: Being in extremely cold temperatures increases the risk as the body temperature falls. Contact with cold ground can also rapidly decrease body temperature.
Submersion in water: Water – especially cold water – causes body temperature to drop faster than air, accelerating heat loss.
Elderly individuals: They may face challenges in regulating body temperature due to other health issues. Difficulty in removing wet clothing or seeking shelter can increase their risk.
-__ Very young children__: Temperature regulation systems are underdeveloped in younger children, leaving them vulnerable to rapid decreases in body temperature in cold conditions.
Poverty: People in impoverished communities may have restricted access to adequate warmth and protection against the elements, increasing their exposure to extremely cold temperatures.
Mental illness: Certain mental illnesses can impair awareness and response to cold, increasing the likelihood of prolonged exposure to cold environments and wet conditions.
Extensive burns: Burn damage to the skin's protective barrier facilitates heat loss, making it difficult to maintain core body temperature in cold conditions.
What are the Signs and Symptoms of Hypothermia?
The symptoms of hypothermia can range from mild to life-threatening, depending on their severity.
There have been many cases of hypothermia that are so severe that people appear dead. This has created the classic saying in the medical community, “No one is dead until they’re warm and dead.”
This insight led to hypothermia sometimes being reversed to treat cardiac arrest, prompting healthcare professionals to explore warming measures as a revival strategy.
Therefore, at-risk individuals found in cold environments should not be immediately presumed dead until they have been warmed up and still show no signs of life.
Key symptoms and signs of hypothermia include:
Shivering
Pale clammy skin
Drowsiness
Confusion
Blue fingers or toes (also known as peripheral cyanosis)
Abnormal heart rhythms or arrhythmias
Signs of water submersion, for example, wrinkled skin or wet clothes and hair
Signs of cold injury, including frostbite
Weak pulse
Cardiac arrest
Key Point: Paradoxical Undressing in Severe Hypothermia
In extreme cases of hypothermia, individuals might undergo “paradoxical undressing” due to feeling falsely warm. They then strip off their clothes whereby they increase their cold exposure, which can hasten life-threatening effects.
The exact cause of this is unknown, but it may involve cold-damaged nerves and dilated blood vessels creating a sense of overheating.
Hypothermia-induced confusion worsens this dangerous response.
How Do You Prevent Hypothermia?
The best way to prevent hypothermia is to remain warm and dry during cold weather conditions. Here are some tips for doing this:
Seek shelter during cold or wet conditions.
Wear warm, insulating clothing when it’s cold or wet outside.
When diving or hiking, ensure that you wear appropriate clothing. If you’re facing extreme weather conditions, it’s crucial to know your limits and follow protocols.
Ensure that the elderly or very young are properly shielded against the cold.
Limit or avoid alcohol consumption as alcohol creates the sensation of warmth but it in reality contributes to heat loss, increasing the risk of hypothermia.
Change out of wet clothing as soon as possible.
Who is most at risk of developing hypothermia?
Certain individuals should be extra vigilant in cold or wet weather as they have an increased risk of developing hypothermia. These individuals include:
Older people
Neonates (children younger than 28 days)
Children
Impoverished/homeless persons
Drug and alcohol abusers
People with mental health issues
High-altitude hikers
Near-drowning victims
What Should You Do if Someone Has Hypothermia?
Severe hypothermia
If you encounter someone with life-threatening hypothermia – characterized by extreme coldness, unresponsiveness, lack of pulse, and fixed pupils – and no immediate rescue help is available, do the following:
First ensure your safety as a rescuer.
Check the victim's consciousness by tapping their shoulders or calling out.
Call for help, requesting an automated external defibrillator (AED) and first aid kit if necessary.
Prioritize contacting emergency services before moving severely ill victims.
If unconscious, check for a pulse; start CPR if there’s no pulse and keep going until help arrives or it's unsafe to continue.
Look for signs of injury; keep the neck still if a neck injury is suspected.
Move the victim to a warm environment, maintaining neck stability.
Remove wet clothing, cutting it off safely if needed.
Dry the victim thoroughly.
Use blankets – including space blankets which can be found in many first-aid kits – to warm the victim, covering their head but leaving their mouth and nose open.
Keep seeking help and aim to get the victim to an emergency care center as soon as possible.
Mild and moderate hypothermia
Someone with mild to moderate hypothermia is treated differently. They may exhibit confusion, weak pulse, increased breathing, and numbness in the extremities. Here’s how to proceed in these cases:
Move them to a warm shelter.
Remove all wet clothing.
Dry them off thoroughly.
Dress in dry, warm clothing that covers their head (especially important for young children.)
Offer warm (not hot) fluids to drink to those who are fully conscious. To prevent choking, avoid giving anything by mouth to someone who is not fully conscious.
Never give alcohol, as it worsens hypothermia.
Use a space blanket, electric blanket, or regular blanket – whichever is available.
Use radiators for additional warmth, if possible.
Always seek medical advice following these immediate measures.
Where Can You Learn More About Hypothermia?
If you or someone around you has been exposed to extremely cold temperatures and suffered the effects of hypothermia, seek medical attention immediately. Once proper treatment has been received, follow all instructions from a licensed healthcare professional.
If you want to learn more about hypothermia, LifeMD can connect you to a team of medical professionals who can provide further guidelines on keeping safe in cold weather.
Book your appointment today to safeguard your health against the cold.
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