What are the health hazards?

Heat exhaustion is a common risk when temperatures are high. It causes dizziness, headaches, shaking and thirst. It is not usually serious, provided that the person cools down within 30 minutes.

A more serious medical emergency is heatstroke when the body’s core temperature rises above 40.6 degrees Celsius (105 degrees Fahrenheit). The condition can lead to long-term organ damage and death. Symptoms include rapid breathing, confusion, nausea and seizures. Who is at risk?

Babies, seniors, active people and those more exposed to high temperatures, such as the homeless, are usually more susceptible to heat-related health risks

Existing conditions, including respiratory and cardiovascular diseases and diabetes, can also heighten risks and be exacerbated by heat.

According to a 2021 study in The Lancet medical journal, heat is the cause for almost half a million deaths a year although data are lacking from many low-income countries.

As many as 61,000 people may have died in Europe due to heatwaves last summer, and a repetition is feared this season as intense heat grips the continent.

“Heatwaves are a silent and invisible killer,” said Professor Liz Stephens, a researcher on climate risk and resilience at Britain’s University of Reading.

“We don’t often see the impact that they have had on human health until the mortality statistics are published many months later.”