Hypothermia
Hypothermia occurs when the body temperature is below 35°C. The normal human body temperature is around 37°C.
Hypothermia
Warning:
Key facts
- Hypothermia occurs when your body temperature drops below normal and your body cannot warm itself up.
- You may get hypothermia from spending long periods of time in cold environments, but you can develop it in any season or environment.
- If you have hypothermia, your symptoms can range from having cool skin and shivering, to becoming confused, having a slow heart rate, slow breathing and losing consciousness.
- Treatment depends on your symptoms and will include being moved out of the cold, being warmed, keeping still, drinking warm drinks if possible or even cardiopulmonary resuscitation (CPR).
- Hypothermia can be prevented by dressing well to suit the weather, taking breaks indoors, keeping hydrated and avoiding alcohol, cigarettes and caffeine.
What is hypothermia?
Hypothermia happens when your body's temperature drops from a healthy range (usually around 37°C) to below 35°C. A drop in body temperature to 32°C or lower can be life-threatening.
Hypothermia can happen in any season or environment — not just in the winter or outdoors.
There are different levels of hypothermia, depending on how low your body temperature is:
- mild hypothermia — body temperature is 32 to 35°C
- moderate hypothermia — body temperature is 28 to 32°C
- severe hypothermia — body temperature is less than 28°C
If you are in a cold environment, your body can usually warm itself up by:
- shivering, which causes muscles to contract
- redirecting your blood flow from your limbs to your organs
- breathing more quickly
- pumping blood faster
When your body loses heat faster than it can warm up, your body temperature drops, and you are at risk of developing hypothermia.
What are symptoms of hypothermia?
If you have hypothermia, your symptoms can develop slowly and will depend on how low your body temperature is. For this reason, you may not realise you have hypothermia.
If you have mild hypothermia, you will be conscious and shivering. You may also:
- have cool skin
- find it difficult to do easy tasks
- struggle to speak clearly
- complain about the cold
- fall easily
You may find the rhyme ‘fumble, mumble, grumble and stumble’ helpful to remember these early warning signs of hypothermia.
If you have moderate hypothermia, you may shiver less and be drowsy and confused. You may also have:
- a slow heart rate and a weak pulse
- an irregular heart rhythm
- stiff muscles
- slow breathing
If you have severe hypothermia, you will be unconscious. You may also have:
- fixed and dilated pupils (your pupils do not respond to light)
- irregular heart rhythm
- vital signs (but a pulse may be harder to detect than normal)
Sometimes, you may also develop frostbite — an injury caused by freezing temperatures that damages skin and body tissues, usually fingers or toes.
What are the warning signs of hypothermia?
If you are feeling cold, clumsy, irritated, tired and are shivering, these are early warning signs of hypothermia. You should seek help and try to get warm immediately.
Warning signs that hypothermia is getting worse include when you:
- stop shivering
- become confused
- slur your speech
- lose consciousness
- have stiff muscles
- have a slow or irregular pulse
When should I call an ambulance or go to the emergency department?
Warning:
What should I do while waiting for the ambulance?
While you wait for the ambulance, if the person is not breathing or has no pulse, begin cardiopulmonary resuscitation (CPR).
Here are some first aid steps while you wait:
- If it is safe, move the person to a warm and dry environment.
- Lie them down horizontally for at least 30 minutes. They should do as little physical activity as possible.
- Remove all wet clothing.
- Begin slow rewarming — cover the person with woollen blankets or a plastic wrap.
- If they are awake and responding, give them warm sugary drinks and food.
- Avoid alcohol, caffeine, smoking and vaping.
Do not warm the person up using direct heat such as a bath, shower or chemical packs.
What causes hypothermia?
Hypothermia happens when your body gets very cold and cannot warm up on its own. This can happen in any season or environment.
This can happen if you:
- are exposed to cold conditions or are drowning
- lie on a cold floor without protection for a long time
- are involved in an accident
- have severe burns
- have a stroke or hormone disorder
You may be at a greater risk of hypothermia if you are:
- an older person
- a baby or young child
- taking certain medicines
- living with diabetes
- under the influence of alcohol or other drugs
- have reduced or no mobility
- have poor blood circulation
Read more about winter health hazards at home.
How is hypothermia diagnosed?
Your doctor can diagnose hypothermia by measuring your body temperature and checking your symptoms.
Tympanic (ear) thermometers may not be able to measure temperature below 34ºC, so your doctor may use a special thermometer to check how severe your condition is.
Your doctor may also recommend some tests, including an electrocardiogram (ECG) and blood tests.
How is hypothermia treated?
Warning:
Treatment for hypothermia depends on how severe your symptoms are.
If someone has mild hypothermia, move them to a warm place, remove any wet clothing, and help them warm up slowly with blankets, warm clothing and warm drinks if they are awake.
If the person is confused, drowsy or unconscious, hypothermia may be more severe than you first thought. Call triple zero (000) and ask for an ambulance.
At hospital, people with moderate or severe hypothermia may need intensive care treatment. The healthcare team will actively rewarm the body using treatments such as warming blankets, warmed intravenous fluids (IV) and oxygen. Other injuries, such as frostbite, will be treated at the same time.
If you need urgent medical attention, but do not need a hospital emergency department, you may be able to get treatment at a Medicare Urgent Care Clinic.
What are the complications of hypothermia?
Hypothermia can cause serious complications including organ failure, arrhythmia (irregular heartbeat), cardiac arrest and even death.
Can hypothermia be prevented?
Hypothermia can often be prevented.
Here are some tips to reduce your risk of hypothermia:
- Check the weather forecast before going out. Make sure you have the right equipment and protection.
- Wear clothing that is right for the weather. Wear loose layers. Check if you need gloves, beanies and water-resistant clothing.
- Make sure to eat and drink enough. If possible, drink warm, sweet fluids.
- Limit the amount of time you spend in the cold.
- Plan 'warm-up' breaks if you work or spend a lot of time in cold weather.
- Avoid alcohol, caffeine and cigarettes — they can make you more sensitive to cold.
- Ask your doctor if your medicines could make you more sensitive to cold.
Read more on dressing your baby in cold weather (Opens in new tab).
Resources and support
Learn more about hypothermia (Opens in new tab) on the NSW Government website.
St John Ambulance Australia has a first aid fact sheet about hypothermia (Opens in new tab).
Read more about preparing for severe weather (Opens in new tab) on the Queensland Government website.
Information for Aboriginal and/or Torres Strait Islander peoples
The Bureau of Meteorology has a website with information about traditional seasonal information (Opens in new tab) for Aboriginal and/or Torres Strait Islander peoples.
Find out how we develop and review our content.
Last reviewed: May 2026
Need more information?
These trusted information partners have more on this topic.
What is the treatment for hypothermia? - myDr.com.au
What do you do if you come across someone with hypothermia? Dr Norman Swan explains the dos and don'ts of first aid for hypothermia.
Hypothermia | Better Health Channel
The early responses to hypothermia will be moving around, seeking shelter, hair standing on end (goosebumps) and shivering.
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