Heat-related health problems

Heat-related health problems

Heat kills more Australians than any other natural disaster. Climate change is resulting in more hot days and more intense heatwaves. Now more than ever it’s important to know the risks of heat and how to protect yourself and others.

Extreme heat can affect anybody. Those more at-risk include people over the age of 65, babies and young children, pregnant women, people with acute or chronic health problems and people who are socially isolated.

Heat-related health problems occur when our bodies can’t cool down well enough to maintain a healthy temperature, or become dehydrated through sweating.

Heat can cause serious and potentially fatal health problems such as heat exhaustion and heatstroke, trigger sudden events like heart attack or stroke, or worsen existing medical conditions like kidney or lung disease.

You can take steps to protect yourself and others by keeping cool, staying hydrated, planning ahead and checking in with others.

People more at-risk of heat-related health problems

Anyone can suffer from heat-related health problems, but those more at-risk include:

• People over 65 years
• Babies and young children
• Pregnant women
• People who have existing medical conditions, such as cardiovascular disease, kidney disease, diabetes, or mental illness
• People on certain medications including diuretics (fluid tablets), beta-blockers, drugs with anticholinergic properties, and central nervous system stimulants
• People who work or exercise outdoors
• People who are socially isolated or living alone, because there may not be someone to support or check in with them during extreme heat.
• People with limited ways to keep cool, such as air conditioning, including people living in buildings that heat up easily or people who are experiencing homelessness.

Causes of heat-related health problems

During hot weather, our bodies work to prevent overheating by sweating and redirecting blood flow to the skin. People can also take actions such as staying cool using air-conditioning, and drinking more water than usual. Heat-related health problems happen when these protective changes in the body, combined with the actions people take are not enough to avoid overheating or dehydration, and organ systems begin to malfunction.

Heat-related health problems occur through several pathways:

• A major rise in body temperature, due to a build-up of heat, leads to conditions such as heat exhaustion, and eventually heat stroke, which is a medical emergency.
• The redirection of blood flow to the skin, means that the heart must work harder than normal. Strain on the heart can cause problems for people with existing heart conditions, for example by triggering a heart attack.
• An increase in sweating can lead to dehydration if fluid loss is not replaced by drinking enough. Dehydration can cause weakness and fainting, lead to kidney problems and worsen other medical conditions.

Symptoms and first aid for heat-related health problems

It is important to know the signs and symptoms of heat-related health problems and how to respond. Symptoms vary according to the type of health problem.

Apply first aid and seek medical assistance immediately if someone shows signs of heat exhaustion, heatstroke or another health emergency.

Deterioration in existing medical conditions

Extreme heat can worsen existing health problems. Conditions that may be triggered or worsened by heat include:

• Heart attack
• Stroke
• Kidney problems
• Asthma and other respiratory illnesses (especially in the presence of air pollution or smoke).

Dehydration

Dehydration occurs when the body doesn’t have enough fluid to carry out its normal functions.

Symptoms of dehydration include:

• Thirst
• Dry mouth
• Passing less urine than usual
• Dark or strong-smelling urine
• Dizziness or headache
• Irritability or difficultly thinking clearly.

First aid for dehydration due to heat includes:

• Move to a cool area and rest.
• Drink plenty of fluids.
• Remove unnecessary clothing.
• Cool down by wetting the skin with cool water.
• See a doctor if there is no improvement or you are concerned.

Heat exhaustion

Heat exhaustion is a serious condition that can progress to heatstroke. It can occur when core body temperature rises to 38-39°C.

Signs and symptoms of heat exhaustion include:

• Heavy sweating
• Pale skin
• Muscle cramps
• Weakness
• Dizziness, headache
• Nausea, vomiting
• Fainting
• Rapid pulse.

First aid for heat exhaustion includes:

• Seek immediate medical assistance by calling NURSE-ON-CALL on 1300 60 60 24 for 24-hour health advice, transporting the person to a doctor or emergency department, or contacting the Victorian Virtual Emergency Department– for non-life-threatening emergencies.
• Call Triple Zero (000) for an ambulance if medical care is unavailable, the person is not improving or if you think they could have heatstroke.
• Get the person to a cool area and lay them down.
• Remove excess clothing including shoes and socks.
• Cool the person down: Wet their skin with cool water, fan continuously, apply a cool, damp sponge or cloth, or apply ice packs or crushed ice in a damp towel on the neck, groin or armpits. If they are able, have the person take a cool shower or bath.
• Encourage frequent sips of cool water.

Heatstroke

Heatstroke can occur when the core body temperature rises above 40 °C and blood flow to internal organs is restricted. Many organs in the body suffer damage and the body temperature must be reduced quickly.

Heatstroke may appear similar to heat exhaustion, but the skin may be dry with no sweating and the person may appear confused or agitated. Signs and symptoms include:

• Confusion or agitation
• Loss of consciousness
• Profuse sweating or hot, dry skin
• Muscle twitching or seizures
• Rapid breathing
• Rapid pulse
• Very high body temperature.

Heatstroke is a medical emergency and requires urgent attention:

• Call Triple Zero (000) immediately for an ambulance.
• While waiting for emergency medical help, get the person to a cool, shady area and lay them down. Have someone stay with the person.
• Remove excess clothing including shoes and socks.
• Cool the person as quickly as possible: wet their skin with cool water, fan continuously, apply a cool, damp sponge or cloth, apply ice packs or crushed ice in a damp towel on the neck, groin or armpits.
• Give the person cool water to drink if they are fully conscious and able to swallow.
• Position an unconscious person on their side and ensure they are breathing normally. If needed, perform CPR. Wait for the ambulance to urgently transport the person to hospital
• If medical attention is delayed, seek further instructions from Triple Zero, ambulance or hospital emergency staff, while waiting for the ambulance.

Heat cramps

Heat cramp symptoms include muscle pains or spasms, usually in the abdomen, arms or legs.

Cramps may occur after strenuous activity in a hot environment, when the body gets depleted of salt and water.

Heat cramps may also be a symptom of heat exhaustion.

First aid for heat cramps includes:

• Rest in a cool place.
• Increase fluid intake.
• Rest a few hours before returning to activity.
• Seek medical help if there is no improvement, the person affected is unwell or if you are concerned, by calling NURSE-ON-CALL on 1300 60 60 24 for 24-hour health advice, seeing your doctor or contacting the Victorian Virtual Emergency Department – for non-life-threatening emergencies.

Heat rash

Heat rash, also known as prickly heat, is an itchy skin irritation caused by excessive sweating.

It can occur at any age but is most common in babies and young children.

Heat rash occurs when the body sweats more than usual.

Heat rash is most likely to occur on the neck, upper chest, waistline, in the groin, under the breasts, and in skin folds and armpits.

The symptoms of heat rash include redness, mild swelling, and a cluster of small red spots in the affected area, associated with itch and prickling sensation.

Symptoms of heat rash can last for several days.

Heat rash normally goes away without treatment. To prevent heat rash and help it resolve faster you can:

• Move to a cooler and well ventilated, less humid environment to cool down and stop sweating.
• Keep the affected area dry.
• Wear loose cotton clothing to help prevent overheating and avoid scratchy fabrics which irritate the skin.
• A pharmacy can recommend treatments to ease itching and inflammation.

If symptoms do not improve seek further medical attention. Call NURSE-ON-CALL on 1300 60 60 24 for 24-hour health advice, see your doctor or contact the Victorian Virtual Emergency Department – for non-life-threatening emergencies.

Preventing heat-related health problems

Take steps to protect yourself and your loved ones from heat-related health problems. Keep cool, stay hydrated, plan ahead and check in with others.

Refer to the How to stay safe in extreme heat page for more information.

Where to get help

• In an emergency, call triple zero (000)
• Your GP (doctor) – if you, or someone you know, may be suffering from a heat-related illness
• NURSE-ON-CALL Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
• Contact the Victorian Virtual Emergency Department – for non-life-threatening emergencies
• Maternal and Child Health Line, Victoria Tel. 132 229 (24 hours, 7 days)
• St John Ambulance Australia – for information and resources on first aid