Insight

Is your organisation ready for the next heatwave?

Published

11 July 2025

Written by

Hannah Nissan Robbie Weston

Read time

5 minutes

Protect your people. Safeguard productivity. Build resilience in a warming world.

As climate change accelerates, more frequent and intense heatwaves are becoming the norm. To protect employees and maintain productivity, organisations need to ensure they have a heat action plan in place.

Data from the EU’s Copernicus Climate Change Service (1) shows just how pressing this is. It found that the planet recorded its three hottest days in July 2024 – breaking the record set one year earlier. With records likely to be broken again and again, the time to act is now.

Extreme heat – the rising risks

Extreme heat is a growing global concern, but heat already causes staggering health risks. Swiss Re’s SONAR 2025 report (2) identifies heat as one of its eight emerging risks. The report points to research (3) showing that up to half a million people die each year because of extreme heat - more than the annual deaths resulting from floods, earthquakes and hurricanes combined.

Known as the ‘silent killer’, these figures are widely under-recognised. Heat can affect the body directly, causing heat exhaustion and heat stroke, which can be fatal. However, many of the deaths are due to the amplifying effect of heat on other health conditions such as asthma, cardiovascular disease, diabetes and mental health, and its true impact is not known until sometime after a heatwave, when epidemiological analyses can take place.

It’s a major issue for employers too – even if many don’t yet recognise the risks. The International Labour Organization (4) estimates that more than 2.4 billion workers – equivalent to 70.9% of the global workforce – will be exposed to excessive heat at some point.

As well as the health risks, heat can also affect productivity. According to the Global Heat Health Information Network (5), productivity starts to slump in temperatures as low as 24-26°C. Once the thermometer hits 33-34°C, you can expect to lose 50% of work capacity.

Extreme heat can mean higher insurance costs too. In its SONAR report, Swiss Re states that heat-related health impacts can increase claims on medical and life insurance while liability claims can also spike, as the probability of accidents increases when workers struggle with heat stress.

Business operations are also at risk. Machinery may malfunction in higher temperatures and the broader infrastructure, whether that’s the energy supply or the road network, can also come under pressure.

Switch on your heat action plan

Given the risks, having a heat action plan is not just best practice, it’s a necessity. Developing a plan for your organisation will ensure you’re able to protect employees and maintain operational continuity. We recommend the following steps to help you develop a heat action plan that is specific to the needs of your business:

Some employees are more vulnerable to extreme heat, so identify the high-risk groups. Outdoor workers and those in poorly ventilated spaces are particularly exposed, but heat affects individuals differently according to a range of factors including their age, pre-existing health conditions and socioeconomic background, as well as where and in what type of building they live. The impacts are nuanced and vary across cities and countries.

Pregnant employees are at higher risk, but consider also the parents of young children. Children can’t regulate their body temperature as efficiently as adults, so you may see more employees choosing to keep them home during a heatwave.

A key part of a heat action plan is having protocols for what to do when a heatwave is forecast, and as temperatures spike. To trigger action, you need to define what constitutes ‘extreme heat’ for your organisation. This threshold will vary between the different vulnerability groups of your workforce (defined in the previous step) as well as by sector: it may be higher for office work than for physical labour or where employees are outdoors. The type and quality of infrastructure will also matter: are your employees working in spaces with air conditioning or passive cooling measures, are they well-ventilated and shaded from the sun? Employees living in cooler countries will experience heat stress at lower temperatures than those more accustomed to warmer climates. The key is to find a workable threshold that balances practicality with ensuring that the most vulnerable are protected and the key business risks addressed.

A heat action plan includes a range of measures that can protect the organisation and its employees from the effects of extreme heat. It should include steps that are taken routinely, such as communication around risk awareness, and ensuring that any machinery and equipment that could be affected by heat, including air-conditioning, is maintained and inspected.

When a heat wave is forecast, other measures can be triggered – these measures will vary across organisations but might include flexible working, rest breaks and hydration measures. Plans should also extend beyond the workplace, looking at how to support employees while commuting, working from home or while resting.

Heat action plans can also consider more long-term measures to build resilience, such as retrofitting buildings with passive cooling measures but also the company’s role in its broader community. Investing in projects that help to reduce heat in the community, for example urban greening and sponge cities, can benefit an organisation’s reputation as well as protect employees, their families and local communities.

A bit of flexibility can make it much easier to cope in a heatwave. As an example, rather than insist employees commute during peak hours, when the risk of heat stress is at its highest, an employer may wish to encourage flexible start and finish times or offer home working, where possible. It’s also worth speaking to employees about how the heat affects them: for some, coming into work may offer respite from the heat of their home so choice can be important. The interventions that work best will vary and depend on how the heat affects your organisation and its employees.

Most people aren’t aware they could be vulnerable, so it’s critical to share information with employees about the risks of extreme heat, the symptoms to look out for and what actions they can take to protect themselves. Training can be provided for staff to understand heat risks, know how to mitigate them and to recognise the signs of heat stress so they can respond effectively in a heatwave.

Review the effectiveness of your plan after each heat event and make changes where needed. It’s also good to encourage employee feedback and seek out best practice to help shape your plans. Similarly, if the nature of your business changes, consider adapting your heat action plan too.

Mom and kid in front of fan

Putting your heat action plan in place

Every organisation needs a heat action plan. Don’t let the complexities put you off. Yes, there are nuances around heat risk such as who is most vulnerable and how best to intervene, but there is a balance to be struck here: understand how heat affects your employees and business, then start simply, with some routine measures and awareness-raising, and work up to more comprehensive heat action plan with protective measures triggered when a heatwave is imminent.

  1. https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024
  2. https://www.swissre.com/institute/research/sonar/sonar2025.html
  3. https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(21)00081-4/fulltext   Global, regional, and national burden of mortality associated with non-optimal ambient temperatures from 2000 to 2019: a three-stage modelling study, Zhao et al
  4. https://www.ilo.org/resource/news/climate-change-creates-%E2%80%98cocktail%E2%80%99-serious-health-hazards-70-cent-world%E2%80%99s
  5. https://ghhin.org/at-work/