Heat-Induced Illness

Heat Induced Illness


Heat-Related Illness is a serious medical condition resulting from the body’s inability to cope with a particular heat load causing the body temperature to elevate above the optimal temperature range and resulting in illnesses caused by overheating the brain and body.

ANCOR recommends in summary, the following practices for Heat-Induced Illness.

First aiders send for an ambulance early in treating heat-induced illness.

• First aiders cool the person by the best means available whilst waiting for more advanced care.

• Give cool/cold water to drink if fully conscious and able to swallow. For exertional dehydration, ANZCOR suggests a 3-8% carbohydrate-electrolyte fluid, such as any commercially available sports drink, power aid supplement, or fruit juice.

Introduction To Heat Illness

Heat-induced illness or heatstroke may be caused by:

• Excessive heat absorption from a hot environment

• Excessive heat production from metabolic activity

• Failure of the body’s cooling mechanisms

• An alteration in the body’s set temperature.

• Failure to hydrate correctly.

Mild elevation in body temperature is normally controlled with sweating, allowing cooling by evaporation. Body temperature can rise rapidly and dramatically once the individual becomes too dehydrated to sweat.

Factors that may contribute to heat-induced illness, such as symptoms of heat exhaustion, include:

• Excessive physical exertion resulting in heat cramps

• Hot climatic conditions with high humidity and extreme heat

• Inadequate fluid intake

• Infection

• Persons who are overweight or obese

• Unsuitable environments such as unventilated buildings, parked motor vehicles, and open fields with no shade or shelter.

• Wearing unsuitably heavy, dark clothing on hot days.

• Drugs that affect heat regulation.

The very young and the elderly are more prone to heat-induced illness. There are occupational health guidelines relevant to the specific environment for workers in outdoor or potentially hot environments. Work environments that may be particularly prone to precipitating hyperthermia and heat-induced illness include those in which there is a high ambient temperature with reduced air movement, where the worker is exposed to radiant heat. There is the difficulty maintaining adequate hydration, such as working in a smelter or furnace plant.

Prevention Of Heat Illness

Under NO circumstances should children, the disabled or the elderly be left unattended in a parked motor vehicle.

Suppose the vehicle is attended, under direct cover and shaded, with the doors open and free airflow and movement, and the vulnerable person is under constant monitoring and supervision. In that case, this is permitted for short durations.

 On warm, humid, or hot days:

• Keep infants and the elderly in cool, ventilated areas and provide ample oral fluids.

• Wear light-coloured, loose-fitting clothing during physical exertion and hats during outside activities.

• Drink adequate fluids during exertion on hot days.

For participants in and organisers of sporting events:

• Allow six weeks for acclimatisation with progressive exercise before a competition

• Avoid vigorous exercise if suffering from an infection

• Plan to conduct events in the early morning or late evening or in the cooler months of the year

• Provide regular drink stations

• Follow the support guidelines relevant to specific activities.

First aid providers may need to prepare for the potential of heat-induced illnesses for specific high-risk events, such as events held in high temperatures. Preparation for such events should include the ability to measure temperatures and provide first aid management.


Heat-induced illness presents with a spectrum of severity. The person may show the signs of exertion (hot, sweats a lot and is breathless) but also have some of these indicators/red flags:

• Inability to continue the activity

• High body temperature

• Dizziness and faintness

• Nausea, vomiting or diarrhoea

• Pale skin and other signs of shock

• Dry skin

• Poor muscle control or weakness

• Decreasing levels of consciousness, confusion, or seizures.

The lack of sweating and the inability to taste salt are signs of serious illness but are only seen in the more serious cases.

Management Strategies 

If the person is not responding and is not breathing normally, commence resuscitation following the ANZCOR Basic Life Support DRSABCD protocols.

The management of heat-induced illness is aimed at cooling and hydration. Cooling the person should be done as soon as practicable but should not delay sending for an ambulance. During cooling management, the level of consciousness and the ability to maintain an airway should be continuously assessed. Cooling management should aim to remove the cause and assist the normal cooling mechanisms of evaporation, conduction, radiation, and convection. Cooling methods will vary depending on availability and circumstance. A combination of cooling methods may be most effective if immersion is unavailable.

Cooling Management

• Lie the person in a cool environment or in the shade somewhere cool.

• Loosen and remove excessive clothing.

• Immerse the entire body from the neck down in cold water (a bathtub as cold as possible without causing cold injury, skin burns or hypothermia) for 15 minutes. This is the most effective method of cooling. If this is not available, a combination of the following procedures should be used:

• Wet the person with cold or cool water, under a shower if safe, or with a hose or other water source.

• Apply ice packs (groin, nape, armpits, facial cheeks, palms, and soles of the feet).

• Repeatedly moisten the skin with a moist cloth or atomiser spray.

• Fan continuously.

While waiting for professional assistance for children five years of age and under, a combination of the following methods should be used:

• Cool in a tepid (lukewarm) bath, frequently sponging if a bath is available.

• Repeatedly moisten the skin with a hose, moist cloth or atomiser spray.

• Fan continuously.

Hydration Management

Oral hydration should only be given if fully conscious and able to swallow. Give cool or cold water to drink if fully conscious and able to swallow. For exertional dehydration, ANZCOR suggest a 3-8% carbohydrate-electrolyte fluid or any commercially available sports drink or power aid supplement.

Plenty of cold water should be consumed orally over the course of the day to reinstate the correct hydration level. However, take caution not to over saturate small children who need less water than an adult due to having a smaller body mass. Excessive water consumption can cause several medical complications, one of which is called hyponatremia, a dangerous drop in blood sodium levels and can, in the worst case, result in death.

Book your course to learn what to do if you or a loved one shows signs of having a heat-related illness.