Red Cross to world's cities: Here's how to prevent heatwave deaths

NEW YORK (NYTIMES) - One of the largest disaster relief agencies on Tuesday (July 16) had a message for the world's mayors: Heatwaves are getting more intense on a hotter planet, but they do not have to be deadly if city officials take simple and often inexpensive steps.

The International Federation of Red Cross and Red Crescent Societies put out a 96-page guidebook designed to help city officials prepare for heatwaves. It repeatedly points out that heatwaves are predictable, sometimes days and weeks in advance, and that city officials, and, sometimes private employers, can take steps to save lives.

The tips include what the federation's president, Francesco Rocca, described as "really simple and affordable" measures. They include knowing when a heatwave is coming; letting people know how dangerous that can be, especially in normally hot places where people might try to shrug off a heatwave; preparing health workers to respond to health emergencies; setting up cooling centres for those without access to air conditioning; and distributing water.

At a time when climate change is exacerbating extreme heat events, the guidebook also offers a reference point for citizens to hold their lawmakers accountable. It comes just weeks after several European cities and towns broke heat records and amid extreme heat warnings for much of the Eastern United States later this week.

Last month was the hottest June in 139 years of record-keeping, according to NASA. If the emissions of heat-trapping gases continue to increase at the current pace, the United States is projected to have twice the number of extremely hot and humid days that feel like at least 100 degrees Fahrenheit (about 38 degrees Celsius), according to a study by researchers at the Union of Concerned Scientists.

Kristina Dahl, the lead author, said the study pointed to "a hotter future that's hard to imagine today".

Heatwaves are most dangerous for those who are already at risk, including older people and the poor. The Red Cross guidebook calls on city governments to identify in advance neighbourhoods and communities that may be more at risk and then to create ways to check on vulnerable people during spikes in heat.

After a deadly heatwave in 2003, Paris directed social workers to do just this. It helped to prevent mass deaths in subsequent heatwaves, including the latest one a few weeks ago.

"Heatwaves are silent killers," Rocca said on Tuesday at a news briefing at the United Nations headquarters in New York. "They take the lives of people who are already vulnerable."

The guidelines also include recommendations to prepare cities for more record-breaking hot days over the long term, for example by painting rooftops and sidewalks in reflective white paint. The book directs one recommendation at employers: Companies, it said, should "add heatwaves to their list of occupational hazards" and especially make allowances for outdoor workers to rest during peak heat hours.

With industrial emissions having increased average global temperatures over the past 150 years, scientists say heatwaves are becoming more frequent and longer-lasting. Heat records are being broken in cold and hot places, and the heat spikes that were once considered rare are becoming more frequent. The worst heatwaves in Europe over the past 500 years, for instance, have all come in the past 17 years.

Especially dangerous for human health is when night-time temperatures do not drop sufficiently to allow the body to cool down. In the United States, summer nights have warmed at nearly twice the rates of summer days.