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Heat stress

Heat Stress is likely to affect people in all parts of Western Australia during our summer months. The effects of heat stress range from simple discomfort to life threatening illnesses such as heat stroke.

Contents

  1. What causes heat stress?
  2. How does heat stress affect me?
  3. Are some people more prone to heat stress?
  4. Factors to consider to control heat stress
  5. How can I avoid heat stress?
  6. How should heat stress be treated?
  7. Should I take salt tablets?
  8. Heat stroke

1. What causes heat stress?

Heat stress may occur as the result of a heat wave or a constant source of heat at the workplace.

Six main factors are involved - temperature, humidity, movement of air, radiant temperature of surroundings, a person's clothing and physical activity.

2. How does heat stress affect me?

High environment temperatures cause an increased blood flow to the skin, which allows release of heat. Blood is diverted to the muscles if physical work is being performed, resulting in a lower release of heat through the skin.

Heat stress also causes increased sweating, depleting the body's fluid and causing heat intolerance. This reduces work capacity and efficiency. Other signs of heat stress include tiredness, irritability, inattention and muscular cramps.

These factors all increase the risk of you having an accident. 

3. Are some people more prone to heat stress?

People who are medically unfit and are on certain medications, overweight, suffer from heart disease, abuse alcohol, or are not acclimatized, are at a greater risk of heat stress and should heed medical advice. Some people are less tolerant of heat than others.

Care should be taken to have a safe system of work that does not endanger or penalise these people.

4. Factors to consider to control heat stress

Inside

  • insulation of roof, walls or other sources of heat;
  • ducting hot exhaust to the outside; and
  • providing fans, ventilation or air-conditioning.

Outside

  • air-conditioned vehicles and rest areas;
  • provision of suitable protective clothing; and
  • sunscreen creams and adequate instructions.

Under the Occupational Safety and Health Act 1984 and the Occupational Safety and Health Regulations 1988, employers are required to provide, where practicable, a working environment in which employees are not exposed to hazards (section 19) and to maintain atmospheric quality (regulation no. 330). employees are required by the same act to take reasonable care to ensure their own safety and health at work (section 20).

Make the Job Safe - Talk about safety and health at work.

If you believe there are problems in this area you should discuss them with your employer and your safety and health representative.   

5. How can I avoid heat stress?

By a few simple principles:

  • Reduce the heat load by replacing fluid loss (drink more water, juices and other non-alcoholic drinks). Drinks of 100-200ml water at frequent intervals will be adequate to reduce fluid loss in sweating;
  • Have rest pauses in a cool place;
  • Help your sweat evaporate by increasing air circulation; and
  • Maintain a healthy lifestyle.

To relieve acute symptoms, such as painful muscular cramps, a solution of one teaspoon of common salt to one litre of water or one teaspoon of electrolyte replacement formula to one glass of water may be drunk. This provides a quick source of salt replacement.

6. How should heat stress be treated?

Have the patient rest in the coolest available place and drink cool but not cold fluids.

Contact a doctor, nurse or first aid officer if the patient does not rapidly improve.

7. Should I take salt tablets?

The National Health and Medical Research Council does not recommend the use of salt tablets, which should only be taken on the direct advice of a physician. Usually sufficient salt is absorbed from food eaten to provide replacement of all salt lost in sweating. However, in cases of extreme sweating, extra salt may be added to food, during cooking or eating.

8. Heat stroke

Heat stroke is the failure of the body to regulate its core temperature.

What are the signs of heat stroke?

Heat stroke is a very serious condition. It is less common than heat stress, but can be life threatening.

A person will stop sweating, body temperatures will be high (oral temperatures 40-43 degrees C), skin will be hot and dry. Confusion and loss of consciousness may occur.

How should heat stroke be treated?

The person should be treated by a doctor as a matter of urgency. Until medical aid is available, cool the person down as quickly as possible, such as by soaking the victim's clothing in cold water, giving cool fluids if the person is conscious, and increasing air movement by fanning.

For further information on heat stress refer to the following documents:

  • Encyclopaedia of Occupational Health and Safety, Third Edition, International Labour Office;
  • Effects of Heat on Health, Comfort and Performance, National Health and Medical Research Council;
  • Protecting Workers in Hot Environments, US Department of Labour 1995;
  • Working in Hot Environments, US Department of Health and Human Services.
  • Guidance Note for the protection of workers from UV radiation in sunlight. Worksafe Australia 1991.

 

 

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