How you can beat the heat
By the time you start sweating, you may already be dehydrated, as PTE John Wellfare reports.

Rehydrate after strenuous activity or exercise, especially in the summer months.

Photo: ABPH Kade Rogers

THE ADF provides some detailed documentation covering the identifi cation and management of heat illness, or hyperthermia (not to be confused with hypothermia, which is cold illness). The information provided here has been taken directly from ADF First Aid doctrine.

Know your enemy

Understanding how to deal with heat illness, according to the experts, is all about understanding how the body’s own cooling system works. The human body has a number of built-in methods for reducing heat, of which evaporation from sweating is one. Others include breathing out warm air and radiation of heat through the skin. Heat illness occurs when these systems fail, or don’t perform adequately.

Precipitating factors

• Physical exertion.
• Hot and humid climatic conditions.
• Inadequate fluid intake.
• Infections.
• Working in poorly ventilated environments.
• Wearing heavy, dark coloured clothing on hot days.
• Taking some medications.
• Being confined to a small, poorly ventilated space.
• Wearing constrictive individual protective equipment.

The manual identifies four different levels of heat illness:

Heat syncope:
A person faints in a hot environment and there is no other identifi able cause.

Heat cramps:
Muscular cramps after physical exertion, while internal body temperature may be normal. Heat exhaustion: Moderately elevated body temperature. Casualty is pale, sweating and thirsty.

Heatstroke:
A very high body temperature, which leads to unconsciousness and death.

We’ll focus on heat exhaustion and heatstroke.

As with all injuries, the first step in the treatment process should always be the DRABC basic first aid principles.

Key warning sign

The key warning sign is a change in mental state.

If someone becomes confused or disorientated, they are at increased risk of heat stroke.

People who display changes in behaviour or mental state should have their activity stopped and be immediately cooled until their mental state returns to normal.

The manuals

Documentation for the treatment of heat and cold illness can be found in the Defence Safety Manual, volume 2 part 1, which is available on the DEFWEB under departmental manuals.

It provides information for supervisors and commanders on prevention of heat illness and management of training and activity in hot environments.

Heat exhaustion

The most common form of heat illness is heat exhaustion. It is caused by fluid loss from sweating, usually through physical exertion without adequate fl uid replacement.

A reduction in body fluids means a reduction in blood volume, which ultimately means less blood gets to the vital organs, so the casualty suffers a mild form of shock.

Signs and symptoms

• Profuse sweating.
• Exhaustion and weakness.
• Dizziness, headache and faintness.
• Nausea and vomiting.
• Rapid breathing and shortness of breath.
• Weak, rapid pulse.
• Pale, clammy skin.
• Skin may be cool to touch.

Treatment

• Move casualty into the shade with circulating air.
• Lie casualty down.
• Loosen or remove unnecessary cloths.
• Sponge with water.
• Give fluids to drink.
• Apply cold packs to the groin and armpits.
• Seek medical assistance if casualty vomits or doesn’t recover promptly.

• Body temperature of 40°C or more.
• Hot, flushed and dry skin, but the casualty may still be sweating.
• Agitation and mental confusion.
• Dizziness and visual disturbances.
• Initially a pounding rapid pulse, which gradually weakens.
• Altered mental state, which may progress to seizures and unconsciousness.

• Move the casualty to a cool area and remove almost all clothing.
• Apply cold packs to the neck, groin and armpits.
• If possible, cover the casualty with a wet sheet and fan to increase air circulation.
• If unconscious, place the casualty in the lateral position.
• If there is no pulse or breathing, start CPR and keep cooling.
• Seek urgent medical assistance.
• Evacuate as soon as possible.

.