The ongoing pandemic amplifies the health risks of hot weather for many people, including those also at risk of COVID-19. Countries and communities therefore need to prepare now for a hot summer. Adjusted communications and outreach strategies will also be needed, as common actions to reduce heat-related illness and death – such as leaving dangerously hot homes for cooler air-conditioned public spaces, home visits to check on vulnerable people, and receiving urgent medical attention for signs of heat stroke – may be impossible or in contradiction to public health recommendations and protocols to reduce the transmission of COVID-19.

To help governments and health professionals prepare for these compounding threats to public health, an information series has been developed to help local decision-makers be more informed about how to manage the health risks of hot weather during COVID-19.

The information series features a technical brief, questions and answers on key issues, and a planning checklist for managing heat risk during the pandemic. It is being launched during a webinar on 26 May, hosted by the WHO Regional Office for Europe, on the prevention of heat health effects in the context of COVID-19.

It addresses the following topics:

Along with the Joint World Health Organization and World Meteorological Organization Office for Climate and Health, and the United States National Oceanic and Atmospheric Administration (NOAA) Climate Program Office, collaborating partners in developing this information series include the International Federation of Red Cross and Red Crescent Societies, Natural Resources Defense Council, C40 Cool Cities Network, as well as academic, public health agencies, and meteorological services from dozens of countries.

Climate Change and Heatwaves

Heatwaves are becoming more frequent and intense as greenhouse gas concentrations lead to a rise in global temperatures, with an increasing toll on human health and health systems. In 2018, vulnerable people over the age of 65 experienced a record 220 million more heatwave exposures, than the average for the baseline of 1986-2005, according to WMO’s Statement on the State of the Global Climate in 2019.

Europe experienced two significant heatwaves in June and late July 2019. France set a new record of 46.0°C on 28 June during the heatwave affecting south-western and central Europe. Much of central and western Europe was impacted in late July. In the Netherlands, this event was associated with 2 964 deaths, nearly 400 more deaths than during an average summer week. In metropolitan France, between the beginning of June and mid-September, over 20 000 emergency room visits and 5 700 home visits by doctors were recorded for heat-related illnesses, according to the WMO report, which included input from WHO and a wide range of other partners.

While environmental conditions likely play a limited role in determining where and when COVID-19 occurs, hot weather can compound impacts and worsen outcomes for COVID-19 patients, could increase transmission rates as people congregate outdoors and in public spaces, and the additional caseload of heat stress patients can place strain on healthcare and other critical systems at a time when many are already at the breaking point. In areas affected by high number of COVID-19 cases, a severe heat event could result in mass casualties and significant health impacts.

COVID-19 has amplified the risks of hot weather for many at-risk groups who are vulnerable to both COVID-19 and heat stress. Due to job losses and extended stay-at-home orders, people considered at risk for heat illness may be in more precarious socio-economic conditions.

Public fear of seeking healthcare during COVID-19 may delay seeking health care for non-COVID-19 related issues even when critically needed. This perception and behaviour could result in preventable deaths of vulnerable persons who are sheltering in place without adequate cooling and not leaving for cooler conditions or health care.

All heat-related illnesses and deaths are preventable, but in the context of COVID-19 approaches should be adapted to local contexts, communications and outreach, and coordination and preparedness are needed.

At the government level, heightened coordination and heat preparedness, including reviewing and modifying heat plans and local guidance should be happening now, before the heat season starts.

In the healthcare sector, medical professionals and other first responders should be trained to watch out for potential heat stress cases, and should be aware of the additional heat risks they themselves may face while wearing personal protective equipment and working in hot conditions.

Reducing the number of people developing heat-related illnesses should be a priority to help minimize admissions to already overstretched hospitals, said Joy Shumake-Guillemot, Joint WHO / WMO Office for Climate and Health Lead and a GHHIN co-coordinator.

City authorities and health professionals are likely to face difficult choices on how to strike a balance between preventing the spread of infection, while also keeping people safe from dangerously hot conditions they may be living in, she also said. This package of information reflecting contributors and reviewers from over 25 countries hopes to help them reflect on their choices and be better informed in their decisions.

At the webinar, hosted by the WHO Regional Office for Europe on the Prevention of heat health effects in the context of COVID-19, Dr. Shumake-Guillemot will present the key concerns of the expert network and considerations for preventive action, along with partners from several European public health agencies who described examples of how they are addressing health risks of hot weather during the COVID-19 pandemic.

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