Extreme heat can cause illness and death. But effective planning and actions can reduce its effects on health.

Health effects from heat

Because the effects of heat are associated with relative rather than absolute temperatures, even in Aotearoa New Zealand’s temperate climate people can experience negative health effects with modest increases in seasonal temperature.

There is no formal definition for heatwaves in New Zealand. But climate change is predicted to cause:

  • both average and maximum temperatures to rise
  • the number of hot days experienced in New Zealand to increase.

Everyone is vulnerable to extreme heat. However, babies and infants, older people, those with pre-existing medical conditions or on certain medications, and people living alone are more at risk.

Many of the adverse health effects from excessive heat are preventable. Under normal warm conditions, the body regulates temperature by producing sweat that evaporates and cools the body. However, when a combination of high heat and high humidity occurs, the evaporation slows and the body must work harder to maintain a normal temperature. This extra work stresses the body and can lead to illness and death.

Keeping cool in heat

Drink plenty of water

Stay hydrated with a regular intake of fluid. Try adding a slice of lemon, lime or mint to a jug of water in the fridge.

Cut down on alcohol

Water is the best form of fluid, alcohol can dehydrate you more in hot weather.

Eat frozen snacks

Try eating frozen banana or other fruit as a cool snack.

Stay out of the sun

Find shade outside wherever possible and stay indoors when you can.

Keep cool while exercising

Exercise or do outdoor activities early in the morning or later in the evening if possible.

Look out for your neighbours

Keep a close eye on neighbours, especially the elderly, to check they’re okay. Remember, children, older people or those with health concerns may find it more difficult to cope with the heat.

Never leave children unattended in parked cars

This is especially important on hot days.

Keep your house cool

Open windows and create a cross breeze or turn on the air conditioning.

Practice being sunsmart

If you have to be outside, remember to Slip, Slop, Slap and Wrap.

  • Slip on a top with long sleeves and a collar.
  • Slip into the shade.
  • Slop on sunscreen that is at least SPF30, broad spectrum and water resistant, and apply 20 minutes before going outside and reapply every 2 hours.
  • Slap on a wide brimmed hat.
  • Wrap on close-fitting sunglasses.

Keep your children cool

As the new school year begins, it’s important to keep your children safe – equip them with a water bottle, appropriate clothing, sunblock and a hat. Perhaps even add a chiller pad to their lunch to keep it cooler for longer.

Look after your pets

Keep them safe, hydrated and cool.

If you have any concerns, call Healthline on 0800 611 116

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