Southeast Australia is enduring a record-breaking heatwave, with temperatures rising above 40ºC in many areas.

For vulnerable people, particularly older Australians, this heat is not only uncomfortable but dangerous. High temperatures can worsen existing health problems and in some cases even prove fatal.

So as the mercury climbs, it’s important to understand why some people are more at risk.

Here’s how to tell if someone is not coping with the heat – and how to stay safe.

Our bodies have a number of processes to regulate temperature.

First, the heart directs blood toward the skin, delivering heat from the body’s core to the surface.

Second, when we sweat and it evaporates off our skin, this allows excess body heat to escape into the air.

But as we age, these processes become less efficient. Older people’s blood flow and sweating are reduced compared to younger people. This means their bodies store more heat for longer.

Often, the real danger isn’t simply overheating – it’s the strain heat puts on the cardiovascular system (the heart, blood and blood vessels) trying to serve two masters.

During hot weather, the heart works significantly harder. It diverts blood to the skin to shed excess heat, while still trying to satisfy the oxygen demands of other vital organs.

This helps explain why, during heatwaves, hospitals are not overrun with older people suffering from heatstroke.........

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