Hot nights matter too: read a heatwave warning beyond the daytime number

The highest temperature in a forecast is only part of a heatwave story. What happens overnight matters too, because cooler nights allow the body and buildings some recovery from daytime heat.

The Bureau of Meteorology defines a heatwave using unusually high maximum and minimum temperatures over three days, compared with the area's climate and recent weather. There is no single daytime number that means the same thing everywhere in Australia.

Read the local intensity

The Bureau classifies heatwaves as low intensity, severe or extreme. Severe conditions are more challenging for vulnerable people, including older people with medical conditions. Extreme conditions can put even healthy people at risk if they do not take precautions.

Those classifications explain risk; this article is not a warning that a particular heatwave is happening now. Check the Bureau's current forecast and warnings for the place where you will be staying.

Plan the cooler place before it is needed

Healthdirect's hot-weather guidance recommends keeping cool, drinking water and recognising heat-related illness. If your home is difficult to cool, consider an accessible air-conditioned public place and check its opening hours and how to get there.

For parents visiting from Nepal, discuss the plan before a hot spell. Does everyone know where drinking water is, how to use the cooling and whom to call? Ask a clinician about individual medical needs rather than changing medicines or a prescribed fluid plan yourself.

Keep the warning and the response separate

A weather warning helps you prepare; it does not diagnose how someone is feeling. Heatstroke is a medical emergency. Call 000 for suspected heatstroke or another medical emergency rather than waiting for the temperature to fall.

The accompanying Bureau video explains heatwave classifications. Use it to understand the terms, then return to current local information for an actual trip, work shift or family visit.