Normal body temperature is between 36 – 37.5 degrees celsius. In normal circumstances, this remains fairly constant regardless of the temperature of our environment through a process called thermoregulation.
The following is a list of temperature variation effects.
Effects of Body Temperature Variation
- 37⁰ Normal body temperature
- 38⁰ Sweating, uncomfortable feeling
- 39⁰ Severe sweating, skin becomes flushed and red – exhaustion and possible convulsions, especially if the casualty is prone to seizures
- 40⁰ Fainting, weakness, vomiting, headache, dizziness, profuse sweating
- 41⁰ Fainting, vomiting, severe headache, altered mental state such as hallucinations, delirium, and drowsiness, sweating stops, breathlessness can occur. At this stage, this is a medical emergency
- 42⁰ Casualty may become pale. Severe delirium, vomiting, and seizures may be experienced. Heart rate will become very fast, and casualty may collapse
- 43⁰ Serious brain damage may occur, or even death. Shock and continuous convulsions may also occur. The casualty may go into cardiac arrest
- 44⁰ (and above) Death is almost certain at this point
- 37⁰ Normal Body temperature
- 36⁰ Mild to moderate shivering, however, this can be within normal limits
- 35⁰ Intense shivering and numbness. Skin will become bluish/grey
- 34⁰ Severe shivering, loss of movement of fingers. Altered mental status may occur, including confusion
- 33⁰ Shivering will progressively decrease and confusion will get worse. The level of consciousness will be altered and the casualty may become groggy. Heart rate will become slower and breathing will become shallow
- 32⁰ Severe alteration in mental status will occur, including hallucinations and delirium.
- Sleepiness will increase, possibly even to unconsciousness. Shivering will stop
- 31⁰ Most likely unconscious. Heart rate will be very slow, and breathing very shallow
- 28⁰ Casualty may appear dead. Cardiac arrest may take place
- 26⁰ (or below) generally death due to respiratory arrest will take place
Overexposure to the sun is a very common cause of injury due to excessive heat. When the temperature is too high for the body’s cooling mechanism to sufficiently cope the body becomes stressed and injury occurs. Heat cramps, heat exhaustion, and heat stroke are three specific stages that the body undergoes during this time.
- Heat cramps can be extremely painful, and can occur anywhere in the body such as the arms, legs, back, and abdomen
- Dehydration or excessive exercise can exacerbate the problem
- Generally, a casualty will show signs of heat exhaustion and cramps
Heat exhaustion occurs as the casualty’s body temperature increases, which can lead to heat stroke. Heat exhaustion can occur very quickly, especially if the casualty has been over-exerting oneself such as working or exercising in the heat.
Signs to look out for include:
- Profuse sweating
- Rapid, weak heartbeat
- Feeling faint
- Nausea, vomiting
- Heat cramps
Management involves predominantly treating heat exhaustion, by:
- Move the casualty to a cool, shaded area and recommend they lie down
- Loosen and remove excessive clothing such as jackets or heavy tops
- Moisten the skin with an atomizer spray or with a damp cloth
- Cool by fanning
- Encourage clear fluid intake such as water if fully conscious
- Call 000 for an ambulance if casualty does not quickly improve
(As per guidance provided by Professor Ian Rogers to the Coroner of Western Australia) Heat stroke is a medical emergency as it may lead to unconsciousness and death. All the body organs may be affected. It occurs generally when the body temperature has reached 40 degrees or above. Heat stroke is an uncommon but life-threatening complication of grossly elevated body temperature with exercise in heat-stressed settings.
Risk is highest with: high temperatures and/or high humidity and/or vigorous activity
Signs & Symptoms include:
- The skin may become dry and hot, but in some casualties profuse sweating is common
- Altered mental state – grogginess, confusion, incoherent speech, dizziness, etc.
- Abnormal walking, coma, or seizures
- Collapse or acutely unwell
- As temperature increases, their mental state will be increasingly affected, and unconsciousness can occur
- Does not recover promptly on lying flat with the legs elevated
If an ill person in a heat-stressed setting hasn’t rapidly responded to lay flat in the shade, there is no downside to assuming heat stroke is the problem and starting first aid. Heat stroke is a medical emergency and the following steps to take in this order are:
- STRIP the athlete of as much clothing as possible
- SOAK with any available water
- FAN vigorously by whatever means possible—improvise e.g. use a clipboard or bin lid.
When available, cool or ice water immersion is the most effective cooling means possible:
- IMMERSE the athlete up to the neck in a cool or ice bath OR
- COVER all of the body with ice water-soaked towels that are changed frequently as an alternative if a bath isn’t available but ice is
- CALL 000 to summon emergency services, but do so once you are certain first aid cooling is being implemented.
Remember it is early recognition and first aid in heat stroke that is critical to save a life.
Some useful differences between Heat Exhaustion and Heat Stroke are as follows:
|Heat Exhaustion||Heat Stroke|
|Skin is moist and clammy||Skin is hot and dry|
|Pupils dilated||Pupils constricted|
Special note for Heat Stroke: An athlete’s skin may feel dry and hot, or sweaty—so the feel of the skin is not a useful sign. Similarly, on-field temperature measurement is unreliable, so don’t use this to rule in or rule out heat stroke
Remember to keep safe in the sun!
- Drink plenty of water
- Sports drinks are also useful as they contain 3-8% carbohydrate-electrolyte fluids, which are lost as the body sweats especially in exertion-related dehydration
- Wear protective clothing – a hat, t-shirt, sunglasses
- Wear sunscreen, and remember to reapply
- Take breaks – don’t go overboard if the temperature is too hot
- Be sensible in the sun
It does not have to be freezing for cold exposure to develop.
Wind and moisture during humid weather or during the rainy season can also rapidly decrease the body’s temperature.
Signs and Symptoms:
- Uncontrollable shivering
- Numbness of fingers and hands
- Loss of function of extremities
- Skin may become bluish/grey and cool
- Impaired coordination, fatigue, lethargic
- Slurred speech
Management of mild hypothermia includes:
- Move the casualty to a warmer location
- Give them a warm drink
- Remove any wet clothing and encourage physical activity to increase body temperature
- Heat packs or hot water bottles can also be used to assist this process
Moderate to Severe Hypothermia
Signs and Symptoms:
- Decrease in shivering, and then loss of shivering altogether
- Increase in muscle stiffness
- Altered mental status – disorientation, grogginess, confusion, etc.
- Decreased pulse and respiration rate
- May lead to unconsciousness
- Low blood pressure
Management of moderate to severe hypothermia Includes:
- Requires urgent medical aid, contact 000 for an ambulance
- Remove casualty from the cold environment
- Follow principles of DRS ABCD where appropriate
- Do your best to warm the casualty
- Remove all wet clothing. Dry casualty if wet
- Place casualty in a dry sleeping bag or blanket
- Give warm oral liquids but not alcohol and only if the casualty is fully conscious
- If the casualty is not shivering and in a remote location, the first aider should commence active rewarming measures:
- Carefully apply external heat. Use either body heat or another heat source (e.g. heat packs) to increase their body temperature
- To avoid burns, ensure that the external heat source is warm/tepid but not hot
- If frostbite has occurred, DO NOT attempt to rub warmth into the affected area as this can cause severe injury to the already damaged tissue
- Do not place the casualty in a warm bath
- If unconscious, follow DRS ABCD