Exposure to the Elements

First Aid Training - Effects of heat and cold

The human body normally regulates its own temperature very well, but can be affected in a number of ways when it suffers the effect of extreme temperature, in particular the very young or elderly are the most susceptible to the effects of heat and cold.

Contact to hot materials/surfaces can cause burns or scalds, the longer the contact the more severe the injury will be. Corrosive chemicals can also cause burns. Exposure to extreme heat can cause conditions such sunburn, prickly heat and possibly heatstroke. Extreme cold can also lead to hypothermia and frost bite.

First aiders should always remember ensure that any danger to you is removed before attempting to commence treatment.

First Aid Training - Prickly heat

Prickly heat is a highly irritating prickly red rash, hence the name, and it most commonly occurs in hot weather.

It is caused by bacteria or dead skin cells blocking sweat glands. The rash particularly affects areas where sweat is trapped and cannot evaporate, such as the feet for instance. People who often have prickly heat also tend to be susceptible to heat stroke.

Recognition features

You can recognise prickly heat by a prickling or burning sensation over the effected area, there will also be a rash of tiny red spots or blisters.


Your main aim is to relieve any discomfort and pain so you should encourage the person to stay in cool conditions as much as possible, and cool the skin by gently sponging with cold water.

First Aid Training - Sunburn


Sunburn can be caused by overexposure to the sun or even a sun lamp. At high altitudes sunburn can occur even on an overcast summer day. Some medicines can trigger severe sensitivity to sunlight and rarely it can be caused by exposure to radioactivity.

Most sunburn is superficial. In severe cases, the skin is a lobster red in colour and blistered - the casualty may also be suffering from heatstroke.


Sunburn is often recognised by:

  • Reddened skin.
  • Pain in the area of the burn.
  • Later there may be blistering to the affected skin.


Your aims when dealing with somebody with sunburn is to move the casualty out of the sun or away from the source of the sunburn and to relieve any discomfort and pain.

Caution though, if there is extensive blistering or any other skin damage you need to seek medical advice.

  • With minor sunburn cover the casualty’s skin with light clothing or a towel.
  • Move them into the shade or preferably indoors.
  • Cool the skin by sponging it with cool water or by soaking the affected area in a cold bath or a cool shower for ten minutes.
  • Encourage the casualty to have frequent sips of cold water.
  • If the burns are mild calomine lotion or an aftersun preparation may soothe them.
  • For severe sunburn obtain medical aid.

First Aid Training - Heatstroke


This condition is caused by a failure in the thermostat in the brain. This regulates the body temperature. The body then becomes dangerously overheated usually due to a high fever or prolonged exposure to heat.

Heatstroke can also result form the use of drugs such as ecstasy.

In some cases heatstroke follows heat exhaustion when sweating ceases and the body then cannot be cooled by the evaporation of sweat. Heatstroke can develop with very little warning, causing unconsciousness within minutes of the casualty feeling unwell.


Recognition features may include:

  • Headache.
  • Dizziness and discomfort.
  • Restlessness and confusion.
  • Hot flushed and dry skin.
  • A rapid deterioration in the level of response.
  • A full bounding pulse.
  • A body temperature above 40 degrees celsius or 104 degrees fahrenheit.


Your aims are to lower the casualty’s body temperature as quickly as possible and arrange urgent removal to hospital.

  • You need to quickly move the casualty to a cool place and remove as much of the outer clothing as possible.
  • Dial 999 or 112 for an ambulance.
  • Wrap the casualty in a cold wet sheet and keep the sheet wet until the temperature falls to 38 degrees celsius, or 100.4 degrees fahrenheit, under the tongue or under the armpit.
  • If no sheet is available, fan the casualty or sponge them down with cold water. Once the casualty’s temperature appears to have returned to normal replace the wet sheet with a dry one.
  • Always monitor and record the vital signs, the level of response, pulse and breathing rate until help arrives.
  • If the temperature starts to rise again repeat the cooling process.
  • Caution though, if the casualty becomes unconscious open the airway and check breathing and be prepared to give rescue breaths and chest compressions if necessary, or if the casualty is unconscious but breathing normally place them into the recovery position, please refer to the relevant tips.

First Aid Training - Heat exhaustion


Heat exhaustion is caused by a loss of salt and water from the body, usually through excessive sweating.

It develops gradually and it usually happens to people who are not acclimatised to hot humid conditions or people that are unwell, especially those with illnesses that cause vomiting and diarrhoea. They are more susceptible than others to developing heat exhaustion.

A dangerous and common cause of heat exhaustion is the excessively high body temperature and other physical changes that result from certain drugs taken for pleasure, such as ecstasy. The user sweats profusely, due to prolonged over activity then dehydration develops leading to heat exhaustion. These effects coupled with the drug’s effect of the temperature regulating centre of the brain can lead to heatstroke and even cause death.


Recognition features may include:

  • Headache.
  • Dizziness and confusion.
  • Loss of appetite.
  • Nausea.
  • Sweating with pale clammy skin.
  • Cramps in the arms, legs and the abdominal wall.
  • Rapid, weakening pulse.
  • Rapid, shallow breathing.


Your aims are to replace any lost body fluids and salt; to cool the casualty down, if necessary, and to obtain medical help.

  • Help the casualty to a cool place.
  • Get them to lie down with their legs raised.
  • Give them plenty of water.
  • Follow if possible with a weak salt solution - one teaspoon of salt per litre of water, assist the casualty to drink it.
  • Even if the casualty recovers quickly, ensure that they see a doctor.
  • If the casualty’s responses deteriorate place them into the recovery position and dial 999 or 112 for an ambulance.
  • Monitor and record any vital signs – the level of response, the pulse and breathing rate.
  • Be prepared to give rescue breaths and chest compressions if necessary.
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