What is heat stress?

Working in hot conditions can be hazardous to health.

Workers who are exposed to extreme heat or work in hot environments (both indoor and outdoor) may be at risk of heat stress.

The terms ‘heat stress’ and ‘heat illness’ are general terms used to describe a range of potentially harmful medical conditions that can happen when the body is unable to cope with working in heat. These medical conditions include:

  • Heat cramps – painful cramps in muscles, caused by heavy sweating that uses up the body’s supply of salt and water.
  • Heat exhaustion – weakness, fatigue, dizziness, visual disturbance, feeling of intense thirst and heat, nausea, vomiting, palpitations, tingling and numbness of fingers and/or toes after exposure to a hot environment.
  • Heat rash (prickly heat) – an itchy rash of small raised red spots on the face, neck, back, chest and thighs caused by a hot and moist environment.
  • Heat stroke – a life threatening condition that requires immediate first aid and medical attention, caused by overexposure to heat and often with dehydration. Symptoms are dry, hot skin, high body temperature (possibly over 41°C) and may include mental confusion which can result in collapse and fitting.
  • Worsening of pre-existing illnesses and conditions.
Back to top