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Heat illness in the field

menu_book picture_as_pdf bookStuart Clark Bushcraft Australia
Issue_2_Dec_2013-18

You and your party are strug-gling – it is oppressively hot on this exposed, rocky ridgeline, and the thought of the riverside campsite only one kilometre away down the spur is all that keeps your legs mov-ing anymore. Your camelback tube suddenly runs dry, signaling the end of your water supply. You know there is a water tank at the campsite – and the river, the river. Without warning, the walker in front of you stumbles and falls forward landing heavily – he cries out in pain and rolls to his side gripping his shoulder. On assessing the walker you find his skin is sweaty and pale, and his breathing is short and fast – he has intense pain in the region of the right collarbone. He also tells you he feels dizzy, weak and nauseous…

Heat illness presents when a person cannot cool her/himself enough to main-tain a normal core temperature. Physical exertion, extremes of heat, poor fluid intake, fluid loss (e.g. sweating), low elec-trolyte balance and improper clothing are all likely triggers in a bushwalking context. Heat-related illnesses include heat rash, heat cramps, dizziness, fainting, heat exhaustion and most significantly, heat stroke which is life-threatening, particu-larly in a wilderness environment remote from medical services.

HEAT ILLNESS IN THE FIELD

Stuart Clark (All Aid First Aid)

18 | BWA December 2013

The most important lesson about heat illness applies to most injuries and illnesses in the field – “prevention is better than cure”. This of course seems obvious whilst reading this article, but when out on the trail in trying, hot conditions, this lesson is often out of focus – in the periphery…this is a truly dangerous situation, and heat illness is not the only risk at this time. Add factors such as falls leading to trauma and the exacerbation of existing medical conditions and the concoction in the remote area is extreme.

Prevention of Heat-related Illnesses

• Keep up your fluids – drink water before, during and after physical exertion in the heat.

• Keep up your energy levels – eat regularly, ensuring you take in electrolytes and sodium.

• Protect yourself – wear a hat and lightweight breath-able clothing and use sunscreen.

• Plan physical activity – ensure your trip is planned around the predicted conditions.

• The buddy system – watch out for each other, rest when someone needs to do so.

Special note about fluid intake

Your body absorbs fluids best when you drink frequently and in small amounts. It also helps with fluid absorption if you drink while eating. Don’t depend on feeling thirsty to tell you when to drink – thirst is a late response of the body to fluid depletion. A good indicator of proper fluid levels is urine output and color. Urine should be ‘copious and clear’. Dark urine generally means you are dehydrated.

Signs and Symptoms of Heat-related Illnesses

• Heat rash – this is a skin irritation caused by exces-sive sweating – it looks like a red cluster of pimples or small blisters occurring on the neck, chest, groin and in bodily creases.

• Heat cramps – these include muscle pains or spasms, usually in the abdomen, arms or legs. Com-monly related to strenuous activity in a hot environ-ment resultant from depleted salt and water. These cramps may also be a symptom of heat exhaustion.

• Dizziness and fainting – heat-related dizziness and fainting results from reduced blood flow to the brain. Heat causes an increase in blood flow to the skin

and pooling of blood in the legs, which can lead to a sudden drop in blood pressure.

• Heat exhaustion – this is a serious condition that can develop into heat stroke. It occurs when excessive sweating in a hot environment red-uces the body’s fluid volume. Warning signs may include paleness and sweating, rapid heart rate and breathing, muscle cramps, headache, nausea and vomiting, dizziness or fainting.

• Heat stroke – this is a medical emergency and requires urgent attention. Heat stroke occurs when the core body temperature rises above 40.5C° and the body’s internal systems start to fail. Most people will have profound central nervous system changes such as delirium, coma and seizures. The person may stagger, appear confused, have a fit or collapse and become unconscious. The symptoms of heat stroke may be the same as for heat exhaustion, but the skin may be dry with no sweating and the person’s mental condition worsens.

Treatment Principles for Heat-related Illnesses

• Assist the victim to rest, preferably in a cool, shaded area.

• Remove outer clothing.

• Wet skin with cool water or wet cloths.

• Give frequent, small sips of an oral hydration solution (water, salt, electrolytes).

• Gently stretch any cramped muscles.

BWA December 2013 | 19

If heat stroke is suspected:

• Commence urgent evacuation preparations.

• Remove clothing and wet the skin with water, fanning continuously.

• If possible, apply cool packs to the groin, armpits and neck.

• Do not give the person fluids to drink.

• Position the unconscious person on their side, clear their airway and monitor breathing.

…Back on the trail, the fallen walker is now resting in the shade of a tree, his right arm in a well-secured sling. With shirt unbuttoned and cool packs in position, he has consumed the majority of the oral hydration solution your group has mixed for him and is recovering from what you assume was quite significant heat exhaustion. You decide that based on his continued recovery a slow walk down the spur to the river is achievable – from there you can organise a car to transport him to the medical centre for assessment.

20 | BWA December 2013