You wont see it in the news headlines - but heat stress could be one of the most dangerous and costly risks of climate change, say our experts at HSBC Global Research.

It’s hot outside and it’s sticky in the office. Your concentration is suffering and fatigue kicks in. But respite comes with a fan and a cold drink.

Meanwhile, millions of people continue to toil away under direct sunlight in the world’s fields and on construction sites – exposing themselves to what is becoming a growing threat globally.

How big is the problem?

Currently, about 300 million people across the world face heat stress conditions, according to Rutgers University data.

If temperatures continue to rise to 1.5°C above pre-industrial levels, this number is projected to rise to c500 million, at 2°C to c800m, and at 3°C it could hit 1.2 billion.

The UK Met Office calculates that if warming reaches 4°C, half the global population could suffer from extreme heat stress.

“Elevated temperatures pose health risks to many parts of the population, but this is a particular issue for people working outside,” says Linnet Cotterill, ESG Analyst for HSBC Global Research.

“The agriculture and construction sectors are most affected, as a lot of the work is outdoors and it often involves high levels of physical exertion and the wearing of heavy protective clothing.”

What is heat stress?

Heat stress can occur when the body is less able to regulate its internal temperature.

The risks increase when the surrounding temperature rises above 26.6˚C on the Wet-Bulb Globe Temperature index – a measure which takes into consideration humidity, solar radiation, and wind speed, as well as ambient temperature.

Symptoms usually range from cramps and exhaustion to heat stroke - and heat stress can be fatal in some cases.

Chronic kidney disease is one of the most severe outcomes - a condition that has been well documented among sugarcane workers in Central America, our research shows.

What can be done?

It could cost a lot, but regulation is increasingly being introduced that could help minimise the risk of heat stress.

Last year, Qatar extended its summer outdoor work ban period and more countries are following suit with new or upgraded rules.

Under proposed EU Sustainability Standards, which are expected to be adopted later this year, companies will need to assess whether heat stress is a material risk to their employees. If it is, they will have to document what they’re doing about it and their plans for managing and mitigating future risk.

“Companies should consider – in both their own operations and their supply chains – whether local laws and regulations are sufficiently protective against heat stress, and implement best-practice policies where they fall short, or do not yet exist,” says Linnet.

Find out more in HSBC Global Research’s report (opens in new window) (opens in new window) (opens in new window).

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