Work Health and Safety Heat Related Illness

Heat Related Illness

Managing the Risk of Heat Related Illness

Heat-related illnesses can occur when the work environment, task or individual’s health prevents the body’s cooling mechanisms from working properly.

If heat is a hazard in the workplace, it should be managed following the standard risk management approach:

  1. Identify the hazard
  2. Assess the risks
  3. Control the risks
  4. Review control measures.

Workers  must be consulted at each step of the process.

During the planning phase of any JCU activity, the activity Supervisor is required to assess all potential risks connected to the activity, including the risk of heat-related illnesses.

Common Heat Related JCU activities include:

  • Field trips
  • Outdoor sports and physical exercises classes
  • Outdoor laboratories, events, workshops, campus tours
  • Working in non- air-conditioned plant rooms, ceiling spaces, sheds and workshops
  • Student placements involving outdoor work
  • Construction, maintenance and grounds work
Key determinants of heat-related illness risks include:Individual factors that should also be considered include:
Previous experience of discomfort or signs of heat-related illnesses by personnel completing the activity;Unacclimatised staff, students and Affiliates – e.g. recent arrival from a different climate, changes to type physical nature of work activities e.g. transitioning from office work to an outdoor project / research work, or individuals returning to work after a period of absence;
Working outdoors in known heat risk conditions including high temperature, elevated humidity, direct sunlight where the participants are engaging in physically demanding tasks, wearing heavy or non-breathable clothing, or there is a lack of access to shade and rest areas;Poor general health;
Working indoors where there is insufficient airflow, high radiant heat sources or restricted/confined spaces, or;Body weight (being overweight or obese can make it more difficult to cope with heat);
During Bureau of Meteorology (BOM) heat warning periods.Age (particularly for people about 45 years or older);
  A low level of fitness will make people more susceptible to feeling the extremes of heat;
 Certain prescription and illicit drug use;
 Medical conditions – people with conditions such as heart disease, high blood pressure, pregnancy, respiratory disease and diabetes may need to take special precautions. People with some types of skin diseases and rashes may be more susceptible to heat.

When assessing the heat risk the activity Supervisor, in consultation with their team, shall consider the following:

  • Are ambient conditions hot, with high humidity?
  • How often can the team take breaks somewhere cool?
  • Is there air movement or breeze?
  • Is the work intense or long (high physical exertion)?
  • Consult directly with the team to determine physical fitness and ability to acclimatise.
  • Do team members wear hot clothing (including Personal Protective Equipment (PPE))?
  • Are the team members qualified, trained and experienced?
  • Do team members have medical conditions or take medication which affects heat regulation (if disclosed)?
  • Is there cool drinking water or electrolytes on hand?
  • Do team members have a good understanding of heat risks and management of these risks?
  • Heat-related illness emergency response processes specific to the location of the activity (e.g. on campus emergency response will include JCU security, field work response may require a trained first aider to be part of the team and suitable equipment to quickly lower core body temperature).

Tools to assist in assessing the risks:

Heat stress tools can be useful. These tools can provide an indication of the level of risk, suggesting that further control is required. They are not an indication of whether work should proceed or not.

Sports Medicine Australia - Extreme Heat

A great resource, developed by the leading Sports Medicine Organisation in the world, discusses assessing heat related illness risk for various physical activities and cooling strategies amongst other topics.

Heat Stress Calculator - eTool from Work Health and Safety QLD

Online calculator to provide guidance on heat stress.

Activity Supervisors, in conjunction with their team, shall consider reasonably practicable controls to eliminate or minimise the risks associated with working in the heat. Any combination of the controls below can be used to manage the risk. A single ‘stop work’ temperature cannot account for all the factors that make working in heat hazardous.

Hierarchy of ControlControl
Elimination Can the risk be completely removed? E.g., cancelling the work task, waiting for the hot conditions to pass, automating the process.
  • Use equipment/plant to reduce the physical demands (e.g., use a ride-on mower instead of a push mower, use earthmoving plant for digging instead of hand shovels)
  • Increase air movement using fans
  • Install air-conditioners or evaporative coolers to lower air temperature
  • Isolate team members from indoor heat sources, for example by insulating plant, pipes and walls
  • Remove heated air or steam from hot processes using local exhaust ventilation
  • Provide shaded areas or temporary shade for work where possible
  • Provide indoor areas or shaded outdoor areas for rest
  • Apply window tinting to windows of vehicles
  • Modify reflective surfaces
  • Insulate/clad sources of radiant heat
  • Work scheduling – Moderate to high intensity physical tasks should be scheduled to avoid the hottest part of the day
  • Job rotation – Rotating team members through tasks to decrease individuals’ exposure time to heat risks
  • Pace of work – Slow down the pace of work if possible
  • Drinking water – Drink water regularly and drink 500ml of water 1-2 hours before any high intensity physical tasks - provide a supply of cool drinking water
  • Supervision – establish buddy systems to allow team members to monitor each other, the higher the heat-related illness risk the higher the level of supervision
  • Increase work break frequency – e.g., for moderate intensity tasks, 10mins drink break every hour (in shaded area, remove protective clothing during breaks, supply of cool water for fluid replacement)
  • Water dousing/immersion – wetting skin with cool water using a sponge or a spray bottle helps increase evaporation or submerge arms and feet in cold water
  • Ice packs/towels – placing an ice pack or damp towel filled with crushed ice around your neck
  • Training, information and supervision
PPE (clothing)
  • Clothing should allow easy evaporation of sweat from the skin - it should be light coloured, light weight and loose fitting, and provide protection against the sun
  • Consider heat risk factors when selecting the PPE
  • Heat reducing PPE can be considered – wearable personal cooling system, such as water-cooled garments, air-cooled garments, cooling vests and wetted garments

Individual Controls

HydrationMedical ConditionsAcclimatisation
  • Drink regularly. NOTE: To encourage drinking, keep fluids within arm’s reach at the temperature that the team member prefers. Most people prefer cool or cold fluids when working in the heat. Water is recommended, however flavour can be used to break monotony (to enhance consumption).
  • Ensure regular food breaks to replace electrolytes. Food can be more effective than electrolyte drinks.
  • Use urine chart to monitor hydration throughout the day.
  • Encourage team members to advise Supervisors of any pre-existing medical conditions that may increase their individual risk of heat-related illnesses.
  • Acclimatisation means that the body is starting to adapt to heat. Every person is different and will acclimatise at different rates. Therefore, those from colder climates who may not be acclimatised should be closely monitored for signs and symptoms of heat illness in addition to the above controls.

The team should continually review the controls implemented to determine if:

  • They are effective in reducing the heat risk;
  • They have introduced new hazards that were not captured during the initial risk assessment; and
  • They are easy to implement and practical for the team.

Other Important Facts

If a worker thinks their workplace is too hot, report using RiskWare.

If a worker is concerned that they are working in an unsafe hot environment, they should alert their immediate supervisor to the problem and discuss some of the possible ways of reducing the impact on themselves and their co-workers.

Australia is well known for its temperature extremes, with scorching hot summers. Working in hot and/or humid environments can be uncomfortable, but more importantly lead to a heat-related illness, which can be fatal.

Fact Sheet - Heat Related Illness

Watch SafeWork South  Australia's Film on Heat Awareness

Heat Stress factors combine to create a total heat load on the body. Heat sources can come from:

  • Humidity
  • Temperature
  • PPE/Clothing
  • Metabolic Heart
  • Radiant Heat
  • Air  Movement

Supervisors and workers should assess these factors and work to eliminate these risks or use other safety controls such as substitution, isolation, engineering or administrative actions to minimise the hazards. Refer to WHS-PRO-002 WHS Risk Management Procedure (Section 3) for more information and guidance on using these controls.

Key controls:

  • Schedule more physically demanding tasks for the cooler parts of the day during November to February
  • Use equipment or plant to reduce physical demands (e.g. ride on mower instead of push mower)
  • Install temporary shade
  • Increase air movement using fan
  • Modify reflective surfaces
  • Increase work break frequency, job rotation of tasks and slow down the pace of work if possible
  • Wear loose fitting, lightweight clothes or self-cooling garments
  • Keep an eye on new coworkers, who are not fully acclimatised to our extremes of temperatures
  • Take breaks during the day in cool, shaded areas or air-conditioned room to bring your core temperature down
  • Try drinking cold fluids or ice slushies before physical activity. Note that cold water and ice slushy ingestion during physical activity is actually less effective for cooling!
  • Water dousing – wetting your skin with cool water using a sponge or a spray bottle helps to increase evaporation
  • Placing an ice pack or damp towel filled with crushed ice around your neck
  • Wrapping in a tarp filled with ice slurry—ice water cooling (immersion and ice tarp ‘taco’) cools the core by 0.2°C per minute, which is twice as fast as enhancing evaporative cooling by covering the body in soaked towels. Great option for field work.
  • TACO method - Reference: Link

You - Self Monitor early warning signsCoworker - What to look for when monitoring others
  • Thirsty
  • Dry Lips and tongue
  • Slowed mental function / low performance
  • Reduced or dark urine
  • 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

Refer to First Aid for the type of action depending on the symptoms.

Suspected heat stroke requires immediate vigorous cooling to avoid neurological damage.

Ice-water immersion is the most effective means of cooling, working twice as fast as evaporative cooling using sprayed water and fans.


First Aid


Heat rash

  • Itchy rash with small raised red   spots on the face, neck, back, chest or thighs.
  • Move to a cooler, less humid environment.
  • Keep the affected area dry and remove unnecessary clothing, including PPE.

Apply a cold compress.

Seek medical advice if symptoms don’t improve


  • Mild to severe thirst (remember   that thirst is satisfied before fluid loss is fully replaced).
  • Dry lips and tongue.
  • Slowed mental function and   lowered performance.
  • Reduced or dark urine output.
  • Drink water. Avoid caffeinated, carbonated and alcoholic drinks, and salt tablets.
  • Loosen tight clothing and remove unnecessary clothing, including PPE.
  • In cases of extreme heat or dehydration, replace electrolytes.

Seek medical advice if symptoms don’t improve or are severe.

Heat Cramps

  • Painful and often incapacitating   cramps in muscles, particularly when undertaking demanding physical work.
  • Stop activity and rest quietly in a cool place until recovered.
  • Eat food or if unable to eat, drink an electrolyte solution.

Seek medical advice if symptoms don’t improve


  • Fainting (heat syncope) can   occur while standing or rising from a sitting position.
  • Lie the Worker flat   immediately with their legs slightly raised.
  • Do not raise the head.
  • Treat as for heat stroke and follow medical advice.

Seek medical advice

Heat Stroke

  • Dehydration, thirst, and   reduced or dark urine output.
  • Sweating.
  • The person stops sweating.
  • Skin can be pink, warm and   dry, or cool and blue.
  • High body temperature above   39 C.
  • Weakness or fatigue.
  • Pounding, rapid pulse.
  • Headache, dizziness and visual   disturbances.
  • Muscle cramps.
  • Nausea and/or vomiting.
  • Clumsiness or slower reaction times.
  • Disorientation or impaired judgement.
  • Tingling or numbness in fingers   or toes.
  • Rapid or short breathing.
  • Rapid weak pulse or heart   palpitations.
  • Vomiting or an unwillingness   to drink.
  • Irritability and mental   confusion.
  • Collapse, seizures and   unconsciousness.

While waiting for the ambulance:

  • Move the Worker to a cool place with circulating air.
  • Loosen and remove excessive clothing, including PPE
  • Immerse Worker in a bath of cold water (whole-body from the neck   down) in a bath of cold water (preferably 1–7˚) for 15 minutes. Continuously   observe the Worker to ensure breathing and conscious.
  • If immersion is not possible, use any combination of the options   below:
    • Cool the Worker by splashing   cool or cold water on their skin or sponging their skin with a damp cloth.
    • Make a wind tunnel by   suspending sheets around, not on, the Worker’s body.
    • Use a fan to direct gentle   airflow over the Worker’s body.  Fan   continuously.
    • Apply cold packs or wrapped   ice to the Worker’s neck, groin and armpits.
  • If the Worker is conscious sit them up to drink cool fluid and   electrolyte solution with sugar.
  • Shivering will make the body temperature rise even further. If   the Worker starts shivering, stop cooling immediately and cover them until   they stop. Once they have stopped recommence first aid treatment.

Call an ambulance immediately