The Rise of Reported Overheating: Why We Need Better Public Risk Communication

Summertime overheating in homes has been identified as a health risk in many temperate regions where domestic air-conditioning is rare, e.g., France, Germany, and the UK [1]. Amongst this group, the UK is ‘dangerously unprepared’ for heat [2] as UK residential buildings are not typically equipped with cooling systems and building design focuses on insulation to reduce heat loss in winter. This absence of cooling strategies within UK housing design is further exacerbated by a lack of a ‘culture of heat’, where people are not fully aware of the effects of extreme heat.

To explore UK household overheating challenges, and their coping strategies, a UK-wide online survey was carried out by Mehri Khosravi, from the University of East London with the University of Bath. This research engaged with more than 1580 households across the UK. Results show that overheating reported in UK dwellings has increased from 20% (2011) to 82% (2022). Behaviour change strategies are still dominant, however, according to the research, the use of air conditioners (AC’s) has increased from 3% in 2011 to 20% during the last decade. If the result of this survey is representative of patterns of AC adoption nationally, this could lead to increased energy use, and pressure on electricity grids while this energy demand has not been considered in the UK policy landscape [3].

Why the UK’s Weather Warning System Falls Short

According to the research, there is a lack of knowledge on how to cope with heat among UK households and this can be due to poor public messaging [4]. Weather warning communication system in the UK only uses colour-only warnings without offering any information about the likelihood and severity of impacts for public [5] which is inadequate for public awareness (Figure 1). This approach can leave the public uncertain about the actual risks and how they should respond. Poor communication, along with low public perceptions of heat-related risks, can contribute to increased mortality during extreme heat periods. Improving public communication needs to be done to reduce heat impacts such as mortality.

Fig 1: Examples of Colour-only weather warning system in the UK

Changing Perceptions: Heatwaves as a Serious Risk

Communicating risks in temperate climates like UK where heat risks are relatively novel, poses a significant challenge and public health messaging does not always appear to have the desired effects as some people do not consider heatwaves as a risk. This positive perception of heat can reduce the effectiveness of public risk communications plans.

Moving Forward: Improving Heat Risk Perception and Communication

The Met Office outlook for 2025 indicates that summer 2025 is likely to be among the three warmest years globally, following closely behind 2024 and 2023 in average temperature [6]. As climate change is increasing the frequency and intensity of extreme heat events, ensuring that UK residents have the knowledge and tools to cope with high temperatures must be a priority.

The findings from this research highlight the urgent need for improved public communication strategies to mitigate the risks of extreme heat. Therefore, calls for better tailored initiatives to deliver heatwave information which could include targeted community initiatives is vital. As approaches to accessing information were found to be diverse across participants. In doing this, it is vital to assess the effectiveness of the heat health alerts, produced by the UK Health Security Agency, in supporting the UK public and communities most at-risk. The results of further assessments into public responses to heat warnings will be invaluable in shaping future policies and initiatives that enhance heat risk education and communication.

Reference:

[1] Lomas, K., Watson, S., Allinson, D., Fateh, A., Beaumont, A., Allen, J., Foster, H., Garrett, H., et al. (2021). Dwelling and household characteristics' influence on reported and measured summertime overheating: A glimpse of a mild climate in the 2050s. Building and Environment, 201(15), 107986.

https://doi.org/10.1016/j.buildenv.2021.107986

[2] Miranda, N. D., Lizana, J., Sparrow, S. N., Zachau-Walker, M., Watson, P. G., Wallom,. H., Khosla, R., & McCulloch, M.(2023). Change in cooling degree days with global mean temperature rise increasing from 1.5°C to 2.0°C. Nature Sustainability, 1–5.https://doi.org/10.1038/s41893-023-01155-z

[3] Khosravi, F., Lowes, R. Ugalde-Loo, C.E. (2023). Cooling is hotting up in the UK, Energy Policy, 174, https://doi.org/10.1016/j.enpol.2023.113456.

[4] Khosravi, F. 2023. Residential cooling in a changing climate: Current practices, future expectations, and policy options. Innovation Fellowships 2022-23.

[5] Taylor, A., Summers, B., Domingos, S., & Garrett, N. (2024). The effect of likelihood and impact information on public response to severe weather warnings. Risk Analysis, 44, 1237–1253. https://doi.org/10.1111/risa.14222.

[6] Madge, G. (2024). 2025 outlook: in top three warmest years on record. https://www.metoffice.gov.uk/about-us/news-and-media/media-centre/weather-and-climate-news/2024/2025-global-temperature-outlook.