The Guardian view on the climate crisis and heatwaves: a killer we need to combat

While Britons don jumpers and complain about the unseasonable cold, much of the world has been reeling due to excessive temperatures. India has been in the grip of its longest heatwave in recorded history, with thermometers hitting 50C in some places. Greece closed the Acropolis in the afternoon last week as temperatures hit 43C; never has it seen a heatwave so early in the year. Soaring temperatures in the Sahel and western Africa saw mortuaries in Mali reportedly running short of space this spring, while swathes of Asia suffered in May.

Mexico and the south-west of the US have also endured blistering conditions; it was particularly shocking to hear Donald Trump pledge again to “drill, baby, drill” at a rally that saw supporters taken to hospital with heat exhaustion. These bouts of extreme weather are increasing as the climate crisis worsens. Although the El Niño weather pattern contributed to heatwaves over the last 12 months, they are becoming more frequent, extreme and prolonged thanks to global heating. By 2040, almost half the world’s inhabitants are likely to experience major heatwaves, 12 times more than the historic average.

These pose a major threat to food security. But the immediate effects are frightening too. There were more than 60,000 heat-related deaths across Europe in 2022, with 4,500 in the UK alone. In the US, 11,000 died last year. Already hot climates in some countries are becoming unbearable. Young, old, pregnant and disabled people are particularly vulnerable to heat-related illness and death. So are the poorest, due to their living conditions and often physically demanding work. Experts say deaths are vastly under-reported and many occur well after temperatures fall. Doctors around the world have reported surging rates of chronic kidney disease related to hard labour in excessively hot and humid conditions. One study found that over a third of heat deaths were attributable to the climate crisis.

The International Federation of Red Cross and Red Crescent Societies and USAid co-hosted a global heat summit this spring to push the issue up the agenda of governments and agencies. Tackling the underlying cause is essential. But so is adaptation to cope with the new challenges. That means everything from redesigning cities – in Colombia, Medellín’s “green corridors” shelter pedestrians and street vendors – to introducing social programmes. Berlin’s 2022 “heat aid” scheme for homeless people provided daytime shelter, cool showers and sunscreen.

Critically, it means protecting workers. A recent UN report estimated that 70% of the world’s 3.4 billion workforce will be exposed to excessive heat at some point. Some countries, such as China and Spain, have specific maximum temperatures above which outside labour must be suspended or extra mitigations must be put in place – even if enforcement is often woefully inadequate. Many more need such measures.

The number of workers who have died in the US due to heat exposure has doubled over the last three decades, yet the US has no federal standards – though the Biden administration has asked the Occupational Safety and Health Association to draft them. Industry lobbyists have battled legislative attempts to safeguard workers’ health. Shockingly, in Florida – the country’s hottest state – the governor, Ron DeSantis, recently signed a bill that bans municipalities from enacting protections such as proper rest breaks and access to water and shade. That’s not just unfair to those now toiling on construction sites and in fields; for some, it may well prove deadly.