How to stay safe as the temperatures soar

As much of southern Australia gets set for a sweltering Tuesday, here's a look at how to deal with the heat.

Beachgoers cool down at Surfers Paradise on the Gold Coast. Source: AAP

What is a heatwave?

The Bureau of Meteorology defines a heatwave as a period of at least three days when the combined effect of excess heat and heat stress are unusual for a local climate.

Are they dangerous?

Heatwaves are the most deadly of all of Australia's natural hazards.

Between 1900 and 2011, 4555 people died from extreme heat in Australia - 55.2 per cent of all deaths caused by natural hazards.

That's more than 1000 deaths higher than the tolls for the next five most dangerous natural hazards combined - cyclone (1285), flood (1221), bush/grassfire (866), landslide (88) and lightning (85).

Who is at risk?

Heat can exacerbate existing medical conditions and can cause heat cramps, heat exhaustion and life-threatening heat stroke.

What can I do?

- drink plenty of water even if you aren't thirsty

- cool off with wet towels and cool foot baths or showers

- stay in cool or air-conditioned buildings if you can

- stay out of the sun in the heat of the day

- avoid strenuous activity and

- check on sick or frail friends, neighbours and relatives

- don't leave people or animals in hot cars