Heat stress

Heat stress can happen when your body overheats and can’t cool itself to its normal body temperature (37°C).

Minor conditions like dehydration and heat cramps to life-threatening conditions like heat stroke can occur.

If you or someone else is suffering from heat stress, you should act quickly.

In Australia, heat has killed more people than all other extreme weather events.

When you're more at risk

In the NT, extreme heat conditions can happen from October to March, putting you more at risk of heat stress.

Heat health warnings are issued by NT Health when the Bureau of Meteorology forecasts unusually high temperatures over a 3-day period.

They are issued using the Australian Warning System.

To check for heat health warnings, go to the Secure NT website and NT Health Facebook page.

Who is most at risk

Groups most at risk include:

• babies and young children
• elderly
• people who:
  • have consumed alcohol 24 hours earlier
  • are overweight
  • have health problems such as heart or lung disease or high blood pressure
  • take certain medications - e.g. for sweat reduction
  • work or exercise outside
  • are pregnant and breastfeeding.

Minor conditions

Minor conditions of heat stress include the following.

Heat rash

An itchy and painful skin rash caused by blockages and increase in pressure of the sweat ducts.

It may look like blisters or red lumps.

Fainting

A temporary loss of consciousness causing reduced blood flow to the heart and brain.

The risk of fainting increases if you’re not adjusted (acclimatised) to a hot environment.

Dehydration may also increase the risk of fainting.

Heat cramps

Heat cramps are painful, involuntary muscle spasms that usually occur during heavy exercise in hot environments.

Fluid and electrolyte loss often contribute to heat cramps.

Muscles most often affected include your calves, arms, abdominal wall and back.

However, any muscle group involved in exercise can be affected.

If you suspect heat cramps:

• rest and cool down
  • avoid strenuous activity for several hours after the cramps go away
• drink clear juice or an electrolyte-containing sports drink
• practise gentle, range-of-motion stretching and gentle massage of the affected muscle group
• seek medical attention if your cramps last longer than an hour.

Major conditions

Major conditions of heat stress include the following.

Heat exhaustion

This is a serious illness which can progress to heat stroke if not properly treated.

It results from an excessive loss of water and salt from the body due to heavy sweating.

Symptoms include:

• profuse sweating
• cold, clammy, pale skin
• fatigue, weakness and restlessness
• headache
• dizziness
• nausea and/or vomiting
• weak but rapid pulse
• faintness.

First aid

If someone is suffering from heat exhaustion, you should:

• lay them down and elevate their legs and feet slightly
• remove tight or heavy clothing
• get them to sip:
  • chilled water
  • a sports drink containing electrolytes
  • other non-alcoholic drink without caffeine
• spray or sponge them with cool water and fan them down
• monitor them carefully.

Contact a health care provider if symptoms get worse or if they don't improve after first-aid measures.

Call 000 if they:

• feel faint, confused or agitated
• can’t drink
• suffer a seizure
• have a core body temperature of 40°C.

Heat stroke (hyperthermia)

Heat stroke is the most serious heat-related illness. It happens when your body can’t control its temperature.

If your temperature rises rapidly to dangerous levels, internal systems start to shut down. This can lead to permanent disability or death without emergency treatment.

Symptoms include:

• high body temperature - more than 40°C
• altered mental state, such as confusion, disorientation, rapid development of unconsciousness
• dry skin - this is not often present
• dry swollen tongue
• rapid, strong pulse at first then weaker
• headache
• dizziness
• nausea
• fits, seizures or coma.

First aid

You should seek medical help urgently. Call 000 immediately.

While you're waiting for help:

• move them to a cool place
• lie them down with legs supported and slightly elevated
• remove clothing
• cool them down rapidly by applying:
  • ice packs to their groin and armpits
  • cool water or wrap them in a wet sheet and fan them
• check their airway, breathing and pulse - if they're conscious
• begin CPR (cardio-pulmonary resuscitation) - if they’re in cardiac arrest.

If they’re breathing and have a pulse, position the unconscious person on their side and clear their airway.

Prevention

To learn how to protect yourself against heat illness, read about living in the heat.

Information for health professionals

To find out more about heat management in places such as residential aged and disability care facilities, go to the NT Health website.