By the time the Australian men's team line up for their World Cup play-off against the United Arab Emirates in Doha on Tuesday night, temperatures are expected to have dropped to 32°C.

While that's cooler than the average daytime high of 38°C, and the two teams will be able to enjoy the luxury of an air-conditioned stadium, it's a brief reminder of why this year's World Cup, which kicks off in Qatar on 21 November, will be the first to be played in winter.

But ahead of the tournament stretches a summer with average high temperatures of around 41°C. In this heat, thousands of workers from South Asia (who make up more than 90% of Qatar's workforce) will continue to toil outdoors, building transport infrastructure, stadiums, hotels and other facilities.

Qatar has faced international scrutiny over its treatment of migrant workers from Bangladesh, India, Nepal, Pakistan and Sri Lanka ever since its successful bid in 2010 to host the 2022 tournament. Hundreds of thousands have come to help build infrastructure for the global showpiece tournament. In addition to the much-criticised "kafala" system of employment, a recurring issue has been the controversy around heat stress and the ongoing refusal by the Gulf state to properly document the deaths of workers.

There is no concrete data from the Qatari authorities to show how many migrant workers have died since the country was awarded the World Cup. In early 2021, The Guardian estimated the figure stood at more than 6,500 since 2010, though Qatar disputes this. Research by Amnesty International found that 70% of deaths remain unexplained. In contrast, official figures from Qatar list just 37 deaths between 2014 and 2020, 34 of which are listed as "non-work related".

Just last month, human rights groups urged FIFA, world football's governing body, to donate $440m - the equivalent of the World Cup prize money - as compensation to the hundreds of thousands of migrant workers who have suffered "abuse and exploitation" while preparing for the tournament.

FIFA president Gianni Infantino recently declared that the hard work of building stadiums makes migrant workers proud, but occupational health experts say more should have been done, and must be done, to protect workers from the deadly impact of heat.

Effects of heat on the body

Dr Jason Lee, an expert in thermal physiology at the National University of Singapore's school of medicine, studies the impact of heat on construction workers. He points to a 2019 scientific study which stated that, across the construction industry in Qatar, three or four Nepali workers die each week.

"It's just not acceptable to simply attribute these deaths to 'predisposing factors'," he says. "To say 'it wasn't the heat, it wasn't the conditions, these are just unhealthy individuals' - I think that is just so wrong. It doesn't make sense that within that group such a high percentage just died. Heat might not be the only factor, but we shouldn't ignore it."

Lee describes the impact of intense heat as vastly underestimated in terms of the problems it can cause, which include chronic kidney disease, heart attacks and respiratory disease. Another issue particularly relevant for building sites is that heat compromises cognitive function, which can lead to an increase in serious accidents.

The impact of heat on the human body depends on a multitude of factors - including clothing, the type and duration of work, acclimatisation, aerobic fitness and a temperature measuring system called the wet bulb globe temperature (WBGT). WBGT measures not just the temperature of a workplace but the likelihood of humans being able to survive in that workplace. It's a measurement that is becoming ever more important in the ongoing climate crisis.

When footballers run up and down a pitch, "20% [of the energy used] goes to actually moving your muscles, and the other 80% turns into heat." This is where the danger occurs. Without an opportunity to rest and cool down, a rise in core body temperature can cause heatstroke - with potentially deadly consequences.

What is true for athletes is also true for the army of migrant construction workers who don't just exert themselves for 90 minutes, but work ten-hour days, six days a week, building futuristic stadiums designed to showcase Qatar and FIFA to the world.

"It's just unconscionable," says Nick McGeehan at FairSquare Research and Projects, one of the human rights groups demanding that FIFA pays compensation to workers. "And it was just so needless. The Qataris knew what the risks were. And they knew what had to be done to put protection in place -and they just didn't do it."

McGeehan has a message for football fans: "If you care about the health and the vitality of the game, then you should care about the fact that its showpiece tournament has led to such huge amounts of harm and loss of life."

New regulations on 'heat stress'

As late as May 2021, new regulations regarding heat were agreed between the Qatari government and the International Labor Organization (ILO). The regulations ban work outdoors between 10am and 3.30pm from June to mid September and state that all work must stop if the WBGT rises above 32.1°C.

However, "there is a naive belief that by establishing a rule, you have solved the problem," professor David Wegman from the Harvard School of Public Health told openDemocracy. "While the society or government may have all the best of intentions in establishing rules or guidelines, the fact that they have been established does not at all provide evidence that they are actually operating."

Professor Wegman also says that WBGT temperature devices are expensive, complicated to use and not used frequently enough. Nor, he says, is the required action always taken when dangerous levels are reached: "While there may be an in-principle or laboratory evidence-based recommendation for 32.1°C, how well this gets implemented is... highly doubtful."

This doubt is reinforced by Dr Natasha Iskander, author of Does Skill Make Us Human?: Migrant Workers in 21st Century Qatar and Beyond and an associate professor of urban planning and public policy at New York University.

Iksander is concerned at the reliance on workers' ability to 'self-pace' - to slow down, drink water, or stop work when needed. "Anybody who has been on a Qatari construction site would not say workers have any ability to self-regulate or hydrate at will - it's just unrealistic," she says. "If you look at regulatory changes without context, they can look like much more than they are."

Iskander says legal structures matter, but they are not what determine the safety of migrant workers, particularly in a country such as Qatar where trade unions are outlawed: "Working conditions are not produced so much by regulatory structure but by a political framework of power dynamics, lack of workers' voices, lack of ability to [permanently] reside in Qatar and the pressures that construction firms themselves face."

Iskander recognises that Qatar is one of the few countries in the world to establish heat regulations, but says workers remain at risk: "If you kept within a safe threshold, you wouldn't be able to do any, or very little, work in the summer months, workspaces would have to shut down. You are negotiating with workers' bodies."

In Singapore, Dr Lee has been collecting signatures from health and labour experts for a statement on the tragedy of worker deaths in Qatar. In addition to deaths that have already occurred, Dr Lee says the global community should be concerned at the long-term prospects for migrant workers who may develop chronic kidney disease and other ailments as a direct result of enduring extremely hot working conditions such as those in Qatar.

Neither FIFA nor the Supreme Committee for Delivery and Legacy (the Qatari body responsible for running the 2022 World Cup) responded to requests for comment.

From openDemocracy