"An extreme heat day is one that is warmer than 90 per cent of all observed temperatures at the site from 1991-2020."

https://www.abc.net.au/news/2024-06-05/world-the-hottest-on-record-12-months-in-a-row/103904150

The interactive map shows the largest number of extreme heat days around the equator where temperatures are already high even without climate change.

Extreme heat days with / without climate change:

127 / 27 DR Congo
135 / 12 Indonesia
180 / 10 Ecuador

39 / 20 United States
30 / 20 Russia

Why the huge increase in days with #ExtremeHeat?

Climate change does two things to air temperature:
1. The AVERAGE shifts to higher temperature. This one is obvious. But also:
2. The VARIANCE gets larger so the extremes become more prevalent

Both of these effects together give a LOT more VERY hot days.

"The world is on track to add nearly two months of dangerous superhot days each year by the end of the century, with poorer small nations hit far more often than the biggest carbon-polluting countries.

But efforts to curb emissions of heat-trapping gases that started 10 years ago with the Paris climate agreement have had a significant effect.

Without them Earth would be heading to an additional 114 days a year of those deadly extra hot days, the same study found."

https://www.9news.com.au/world/weather-world-is-heading-to-add-57-superhot-days-a-year-but-study-indicates-it-could-have-been-worse/4410926b-de5e-4142-adb0-e849e8ac2ea9

A sobering preview’: extreme heat now affects one in three people globally, study finds

"Rising temperatures making it hard even for young, healthy people to safely do normal physical tasks in many regions

Within countries there are huge variations according to geography, income group and types of work."

https://www.theguardian.com/environment/2026/mar/10/extreme-heat-study-global-warming-physical-activity

Extreme heat identified as "the most urgent and rapidly growing risk to health and livelihoods across the Southern African Development Community.

A key finding of the study is that extreme heat acts like an "integrator hazard" - a risk that multiplies multiple climate related challenges at once."

https://africasciencenews.org/extreme-heat-emerges-as-a-major-climate-and-health-threat-in-southern-africa/
#ExtremeHeat

"All six heatwaves included periods that would not have been survivable for people aged over 65 remaining outside in full sun [for six hours].

The Larkana and Phoenix heatwaves included periods that were not survivable for older people even if they had found shade.

The Larkana heatwave included a non-survivable period that would have been deadly for people aged 18 to 35 in full sun."

https://www.theguardian.com/environment/2026/apr/08/extreme-weather-heatwaves-breaching-human-survival-limits-study-finds

"Our study was unique because it brought together evidence from across health, labour, food systems and infrastructure to show how heat affects everyday life, analysing heat not just as a weather event, but as a system-wide risk.

In our report, we describe extreme heat as an “integrator hazard” (a multiplier). This means it is not only one risk but makes existing problems worse all at once."

https://theconversation.com/extreme-heat-is-a-growing-threat-to-health-jobs-and-food-security-in-southern-africa-study-looks-for-practical-solutions-280339

"This report uses ‘lethal humidity’ as a focal concept.

The report’s main objective is to show that those impacts aren’t isolated: they cascade through societies, magnified by other climate hazards, such as storms and flooding."

https://www.aspi.org.au/report/lethal-humidity-and-the-systemic-risks-of-climate-change/

"HEAT exposure could drive a dramatic rise in cardiovascular disease (CVD) burden across the USA over the next 25 years, with researchers warning that climate change and population ageing may combine to reverse decades of progress in heart health."

https://www.emjreviews.com/en-us/amj/cardiology/news/climate-change-could-triple-cardiovascular-disease-burden-by-2050/