What was once an occasional hazard has become, for a vast share of the global labor force, a routine condition of working life: The International Labor Organization (ILO) estimates that more than 2.4 billion workers — roughly 70 percent of the global workforce are exposed to excessive heat on the job. Yet exposure on that scale is anything but evenly shared. Heat is where the climate crisis and the inequality crisis meet, because the people most likely to suffer and die from it are, with striking consistency, those already disadvantaged by income, gender, race, or migration status — the same people who contributed least to a warming planet and who have the fewest means to protect themselves from it.

Farmworkers in the United States are a case in point. Oxfam’s research  Exposed and Unprotected, has documented how they came to be among the most heat-exposed workers of all — a result not only of punishing physical labor performed through the hottest hours of the hottest months, but of their historical exclusion from protections that have been afforded to other sectors. The toll is considerable: by some estimates, agricultural workers are as much as 35 times more likely to die of heat than workers in other industries, and that risk falls unevenly, on a workforce drawn disproportionately from communities of color. Even so, as Oxfam’s recently-published Best to States to work in the US report show, the safeguards that might prevent such deaths exist in only a handful of states, and there is still no federal heat standard.

A similar pattern runs through the supply chains that stock the shelves of the world’s largest brands. In hot regions everywhere, the people who harvest what we eat — waged and seasonal laborers, informal workers, smallholder farmers — are commonly paid for what they produce, on schedules set well above them. In Malawi’s Lower Shire Valley, for instance, Oxfam has been listening to smallholder sugarcane growers whose cooperatives supply both local and international markets. There, the harvest of sugarcane coincides with the hottest months of the year, and because growers are paid for the volume of cane they deliver on schedules they cannot easily change, the incentive is always to keep cutting through the heat. The difficulty, in such cases, is rarely the temperature alone; it is that those most exposed to it tend to have the least ability to improve their situation.

It is often in these situations that the conventional response often falls short. Confronted with heat, we tend to reach first for a technical remedy — a cooling vest or a fan. The more pertinent question is whether workers are able to use what they are given. In Hong Kong, for instance, Oxfam and local partners have helped build a heat-monitoring network for the city’s outdoor cleaners. This included working with a health technology company to install Wet Bulb Globe Temperature Sensors across the districts that feed more accurate, localized, real-time alerts to outdoor workers through smartwatches, pairing location-specific warnings with the wearer's own signs of heat strain. While workers using the watches responded to the prompts by taking breaks and hydrating, some workers reported being issued cooling vests and then prevented them from wearing them because the vests obscured a company logo. The equipment was available; what was lacking was the latitude to use it.

None of this is to discount the fundamentals, which demonstrably save lives. For instance, La Isla Network has spent close to two decades showing that in sugarcane work in Latin America, reliable rest, shade, and water can reduce heat-related kidney damage substantially — and without any corresponding loss in productivity. Yet such measures, essential as they are, can only accomplish so much, because the deeper determinant is power: whether a worker is in a position to stop when their body is at risk, earns a wage that makes resting affordable, has a collective voice through a union, and is shielded from retaliation for raising concerns or declining unsafe work. The evidence is instructive — researchers studying workers in Cambodia across multiple sectors found that those whose unions had bargained over heat exposure was better protected than those without. Where workers have such protections, they can act on the risks around them; where they do not, additional equipment tends to make little difference.

The challenge, then, is to look beyond the immediate hazard and consider what genuinely enables people to protect themselves. For companies that begins with recognizing heat as a human and labor rights risk and following it the full length of the supply chain if it is assessed to be a salient risk in their supply chains— past the first tier of suppliers to the informal and smallholder workers who are most exposed — engaging those workers and rightsholders directly, as the people who understand their own conditions best, and taking account of the distinct ways heat affects women. It also calls for an honest look at purchasing practices, since no supplier or smallholder can reasonably be expected to guarantee rest, shade, and adjusted working hours while being pressed on price and held to an inflexible schedule. As one recent study by Siers noted, brands in the garment sector overwhelmingly acknowledge heat as a business risk, yet only about a third go so far as to ask their suppliers to measure the temperatures their workers endure.

Ultimately, a resilient supply chain is not one in which the crop withstands the heat, but one in which the people who tend it do — with their health, their dignity, and their rights intact. The tools to make that possible are, for the most part, already within reach. What remains is the harder work of ensuring that the workers who need them most are genuinely able to use them.