“One hot day doesn't necessarily cause us a massive problem. What we get is a buildup of heat, which then takes time to dissipate. Our infrastructure is not set up for nighttime cooling.”
Chris Todd is chair of the Health Estates and Facilities Management Association, based in the United Kingdom of Great Britain and Northern Ireland. He sees how extreme heat, such as that experienced in the WHO European Region this summer, impacts all health care facilities from primary care to hospitals, as well as the social care facilities to which vulnerable older people are often discharged.
Overheating within buildings themselves can compromise the safety, comfort and well-being of patients, residents and staff. However, extreme heat can also overwhelm technology. This includes digital record-keeping systems and the cooling of sensitive medical equipment, potentially causing outages and disruption to continuity of care. Heat can also affect supply chains, leading to problems with the availability of crucial products.
In 2026, WHO issued revised heat–health action plan guidance to support countries to build health systems that are resilient to a warmer present, characterized by increasingly hot summers and more frequent heat extremes, while preparing for further temperature rises in the future.
Building and system design
In the face of rising temperatures caused by climate change, heat solutions for health systems cannot be focused on response alone; resilience to extreme heat must be embedded in routine health system planning, operations and infrastructure decisions.
Given the huge variety in the design and age of the buildings that Chris oversees, different challenges present themselves during heatwaves. Measures that are effective in other settings may not be readily transferrable to health care facilities, where infection prevention and control requirements, as well as specific ventilation standards, can require other types of cooling strategy, such as building design and passive cooling.
“If you go into a department store, yes, it’s lovely and cool, but it's all recirculated air – air that's been chilled and then chilled again, repeatedly”, says Chris. In hospital settings, using recirculated air may come with an infection prevention and control risk because it can move viruses and bacteria from one patient room into another, unless air conditioning is operated with highly effective filtration systems: “One of the biggest challenges is being clear on the priority. Is it the infection prevention control element or is it the temperature to support well-being? The answer is of course both. They are both our priority. But those are the really difficult conversations that we're having.”
Chris and his team conduct regular, real-time facility checks. To ensure the well-being of staff, cool rooms have been established where they can rest, and fresh water is always available. Cooler wards are available for those in recovery. Temporary chillers have also been brought in, although these can put pressure on this equipment, which was not designed to cope with such sustained high use.
Ongoing challenges
As this summer’s unprecedented series of heatwaves in the European Region showed, periods of extreme heat place multiple pressures on health systems. For example, older people or those with comorbidities can be badly affected by heat so that heatwaves increase demands for services.
Heatwaves can also affect certain clinical procedures. For example, orthopaedic operations need cement to dry in a certain time frame. If the cement is drying too quickly because of the heat, clinical activities must be delayed. Heat can also disrupt community outreach services by reducing the capacity of health workers to safely conduct patient visits and other outdoor activities, affecting continuity of care and service delivery.
“In their own homes, individuals can go through routines to adapt to hot weather, such as lowering blinds or shutters during the day or opening windows at night, but the hospital environment makes this harder to achieve. Health and safety requirements may limit the opening capacity of windows so rooms can't be effectively cooled. Equally, when outdoor temperatures remain high, ventilation systems may draw warm air into buildings, reducing cooling opportunities and contributing to overheating.”
In these cases, national severe weather warnings are a tool that can help hospitals schedule sensitive procedures to avoid periods of extremely high temperatures.
Forewarned is forearmed
Ties Eikendal is an emergency physician at the University Medical Center, Radboud MC in Nijmegen in the Netherlands (Kingdom of the). He says that although the public sometimes mocks weather alerts issued by the Royal Netherlands Weather Bureau, they make a big difference.
“There are three levels. Yellow means be cautious; orange means this is serious, and red means there are very serious consequences due to weather problems. If it's in winter, it gets slippery due to ice forming. If it's unexpected, my emergency department at 8 o'clock in the morning is completely filled with people falling off their bikes going to work. If the evening before there is an orange weather code saying it's going to be slippery, be careful, my emergency department at 8 o'clock in the morning is empty. So, it does work.”
The same protective effect is seen when alerts are issued about hot weather. Ties shares his observations: “If it's red, the Weather Bureau advises people not to go out and so they stay in. It’s not regulatory, it's not law, but there’s an understanding that if it is a red situation, it affects life. So, if you're not able to get to work, it is accepted.”
He notes that, in his experience, the advice helps guide risk behaviours among elderly and other vulnerable people, so they are more likely to stay at home if a cooler environment is available, and to drink more.
Ties describes how heat alerts give his team time to prepare: “We bring in extra materials to treat heat-related problems. We treat heat stroke with towels, drenched in water, so we'll make sure that there's enough water, enough towels, enough fans. We have an ice bath, which we bring into the emergency department.”
Ties believes that heat and the other health impacts of climate change such as floods, droughts and food shortages are only just beginning to be felt, and that they will get worse. As an early warning for health systems, heat alerts will be useful if agreed standard procedures are established and implemented after a notification is issued.
“There's going to be problems that we cannot foresee, or that we don't want to foresee, that are going to pose a problem for health care.”
Heat–health action plans
“The European Region is warming at more than twice the global average. Heatwaves will get more frequent, intense and last longer, and health systems must be prepared to stay resilient”, says Oliver Schmoll, Programme Manager at WHO Regional Office for Europe’s Centre for Environment, Climate Change and Health.
During heatwave-related spikes in health care needs, health systems must be able to continue delivering safe and effective care, which can put pressure on workforce and infrastructure. At the same time, health care workers are exposed to occupational heat risks that may affect their safety and their capacity to do their jobs. The risks are compounded by the general effects of heatwaves, such as sleep deprivation, which they are experiencing outside of work.
“We have proven tools to strengthen health systems and save lives. WHO heat–health action plan guidance promotes a resilient approach to managing heat and integration across health system planning, infrastructure, workforce capacity, and service delivery. It is now time to put heat–health action plans in place to ensure that essential services remain safe, accessible and operational during extreme heat and in an increasingly warmer climate.”