Labour’s flagship Employment Rights Bill is currently in the final stage of its legislative journey in the House of Lords. Peers are making a final round of amendments to the bill — hailed by the Government as the ‘biggest improvement in workers’ rights for a generation’ — in the wake of a sweltering heatwave that has scorched much of Europe. 

With temperatures recently soaring past 40 °C in countries like Spain, Italy, France, Portugal, and the UK nearing 35 °C (just off the back of the second hottest June on record), many parts of the continent have issued serious weather alerts and taken measures like closing schools or winding down nuclear power operations. This extreme event — fuelled by a persistent ‘heat dome’ over the continent — is testing the resilience of public health systems, infrastructure, and adaptation strategies; all while we are warned that such conditions are set to become increasingly frequent under climate breakdown.

While it has been watered-down considerably from what many initially hoped, the Employment Rights Bill represents a rare positive intervention from this government. But, as temperatures rise, there remains a glaring gap in the legislation: provisions to ensure worker safety in very hot weather.

Recent research at the Autonomy Institute has found that, in the coming decades, millions of workers in the UK will be exposed to dangerous working temperatures. By the end of the 2020s, we found that almost two-thirds of UK workers could find themselves working in extreme heatwaves, with temperatures above 35 °C. By 2050, extreme summer heatwaves could leave 27.1 million workers exposed to dangerous temperatures.

Our findings underscore the desperate need for new legislation to ensure workers are not forced to work in unsafe conditions. We’ve set out possible measures in our recent report, Extreme Heat. Most urgent is the introduction of a statutory maximum working temperature above which work is legally categorised as unsafe. Guidance from the Trade Union Congress has suggested that normal, acceptable working temperatures range between 16 °C and 24 °C. It suggests a maximum working temperature of 27 °C be adopted for outdoor strenuous work, and 30 °C for all other work.

At the same time, employers should have a legal obligation to protect outdoor workers from the worst effects of the heat, and the hottest parts of the day. This means providing shelter from the sun and drinking water. It might also mean pausing work at the hottest times of day.

The risks of working in extreme heat are varied and become progressively severe at higher temperatures. Even in the high 20 degrees centigrade, research shows an increased risk of workplace accidents, as well as a drop in productivity, resulting from poor concentration and tiredness. What can appear like small things — such as sweaty palms — can make it more likely that workers will slip or drop things. But as temperatures become extreme we begin to see more direct risks to health: an increased risk of heatstroke or collapse, confusion and ultimately a risk of severe organ damage or even fatality.

Unsurprisingly, outdoor workers — especially construction workers and cleaners — are the most exposed to extreme heat. By 2040, more than one million of these workers are likely to be working in temperatures above 27 °C throughout the summer, not only during extreme weather events. This marks the establishment of a dangerous ‘new normal’ which will inevitably lead to deaths if measures are not taken.

While the UK continues to get hotter, our buildings remain poorly suited for these hot summers. Because of this, in addition to those directly exposed to the heat outdoors, millions of office workers are also vulnerable to the hot weather. Current legislation suggests temperatures inside buildings should be ‘reasonable’, but reasonable working temperatures are not themselves defined. Defining a legal maximum working temperature would incentivise employers to properly equip their buildings for hot weather, meanwhile extending existing domestic retrofit programmes to workplaces would help to reduce reliance on air conditioning systems to achieve this.

Defining safe working temperatures is not a particularly radical suggestion: in the UK we already have defined minimum working temperatures. While these only exist as ‘guidance’, employers are nonetheless far more likely to intervene in very cold weather than in hot weather. Similarly, defined maximum temperatures already exist elsewhere in the world. In Spain, for instance, 27°C is defined as the maximum temperature for sedentary work and 25°C for light physical work.

While the guidance approach which has been adopted for minimum working temperatures means employers do sometimes intervene, establishing a legal definition of maximum working temperatures is likely to be far more effective. It would hand trade unions the tools they need to intervene in unsafe working environments before workers are seriously harmed by unsafe conditions.

The Employment Rights Bill is not yet law, and there is still time for the Government to make a decisive move to upgrade the UK’s climate resilience and protect millions of workers. Indeed, in the past few weeks the government has confirmed that it is adding new provisions for parental bereavement leave to the legislation. With climate breakdown already here — and worse to come in the following decades — there’s no excuse to avoid decisive action.