A mother cools off from the heat with her child playing with water around a fountain in Athens. AFP

The WHO also urged governments and local authorities to set up a strong surveillance system for people who are most at risk of severe symptoms from a heatwave that is baking the northern hemisphere.

People with cardiovascular and respiratory diseases and diabetes, as well as pregnant women, children and homeless people, are seen as the most vulnerable to heatwaves that have scorched parts of Europe, Asia and the United States this week.

Meanwhile, Italy put 23 cities on red alert with temperatures set to reach up to 46˚C, one of the global hotspots as a wave of extreme heat, wildfires and flooding wreaks havoc from the United States to China. The heat wave has hit southern Europe during the peak summer tourist season, breaking records — including in Rome - and bringing warnings about an increased risk of deaths.

Wildfires burned for a third day west of the Greek capital Athens and firefighters worked throughout the night to keep flames away from coastal refineries.

The WHO said the heat often worsens pre-existing conditions, saying it was particularly concerned about those with cardiovascular diseases, diabetes and asthma.

Millions of people across three continents are enduring a sustained spell of dangerous heat on Wednesday as temperature records tumble.

“Extreme heat takes the greatest toll on those least able to manage its consequences, such as older people, infants and children, and the poor and homeless,” said WHO chief Tedros Adhanom Ghebreyesus. “It also puts increased pressure on health systems,” he told a news conference.

“Exposure to excessive heat has wide-ranging impacts for health, often amplifying pre-existing conditions and resulting in premature death and disability.”

The WHO was working with the World Meteorological Organisation (WMO), its fellow Geneva-based UN agency, to support countries in developing hot-weather action plans to coordinate preparedness and reduce the impacts of excessive heat on health, he added.

FINDING THOSE AT RISK

Maria Neira, the WHO’s public health and environment chief, said the agency was particularly concerned about pregnant women and people with diabetes and cardiovascular diseases, and asthma, as air pollution would be part of the problem.

Local and national governments needed to identify all those potentially at risk, while hospitals should ensure they had an action plan in place, she added. Neira also said communities needed to get the message out on avoiding sport during the hottest part of the day, finding a cool place indoors, looking out for the vulnerable, and being aware of heat stroke or heat exhaustion.

While the El Nino weather phenomenon has been seen as the reason for the heatwave this year, global warming has been further exacerbating the issue, causing erratic weather patterns globally.

While some are facing heatwaves, heavy rains have pummeled central and southern regions of South Korea since last week while in northern India, flash floods, landslides and accidents related to heavy rainfall have killed more than 100 people since the onset of the monsoon season on June 1. “In the medium and long term, we need to decarbonize our society as well,” Neira said.

CLIMATE CHANGE BLAMED

Experts have blamed the heatwaves on climate change, driven by the burning of fossil fuels releasing the greenhouse gas carbon dioxide into the atmosphere.

Besides immediate measures to cope with the heat in the coming days, Neira said that in the longer term, countries needed to decarbonise to mitigate the causes of climate change, which is “exacerbating and increasing the frequency, the intensity and the duration of those heatwaves. “That will be helping us to reduce the heatwaves in a very important way.”

City officials needed to think through their urban planning to ensure people had refuges in times of extreme heat, she added. The UN’s WMO weather agency has said repeated high overnight temperatures are a particular health risk because the body is unable to recover from hot days, leading to more heart attacks and deaths.

Agencies