UN warns 40% of England adults take no action on heat alerts

Richmond Hill, Ontario, Canada, 14 August 2026 — England’s heat-warning system is reaching millions of people, but a new investigation suggests that many recipients still do not believe the danger applies to them. Among adults who reported seeing a Heat Health Alert, 41% took no action to protect themselves, according to a national survey analysed by experts at the United Nations University Institute for Water, Environment and Health (UNU-INWEH). The finding exposes a critical weakness in heat-risk communication: awareness of a warning does not necessarily produce behaviour that reduces exposure, protects vulnerable people or prevents heat-related illness.

The investigation, published as Strengthening England’s Heat Resilience: From Warnings to Long-Term Adaptation, combines survey data from adults in England with interviews involving professionals responsible for communicating heat risks. Around seven in ten people surveyed said they had encountered a Heat Health Alert. Yet the most common explanation among those who did nothing was not that the message was inconvenient or impossible to follow. Instead, many respondents said they did not consider themselves personally vulnerable to high temperatures. That response points to a psychological barrier at the centre of the problem: people may recognise that heat can be dangerous in general while excluding themselves from the group they believe is at risk.

The results arrive after a summer that placed England’s heat-health infrastructure under exceptional pressure. On 26 June, a provisional maximum temperature of 37.7°C was recorded at Lingwood, Strumpshaw Hill, breaking a June record that had stood since 1976. England was also placed under only the second Red Heat Health Alert since the current alert system was introduced. At Hastings, the minimum temperature reached 23.2°C, setting a new June record for the warmest night. Such high overnight temperatures are medically important because the body depends on cooler conditions during sleep to dissipate stored heat and recover from daytime thermal stress. When homes remain hot through the night, physiological strain can accumulate, especially among older adults and people with underlying illnesses.

Another spell of extreme heat in August prompted widespread amber alerts across England, again bringing attention to the country’s exposure to increasingly intense heat events. Heat is not simply an issue of discomfort. The human body maintains its core temperature through mechanisms including sweating and increased blood flow to the skin. In hot conditions, evaporation of sweat becomes the principal route for losing heat, but that process becomes less effective when humidity is high or when people cannot access water, shade or ventilation. Older people may have a reduced ability to sweat or regulate circulation, while cardiovascular, respiratory, renal and neurological conditions can make thermal stress more dangerous. Some medications can also affect hydration, sweating or blood pressure, meaning that heat risk depends on health, housing and social circumstances as well as the temperature shown on a weather forecast.

The UNU-INWEH analysis found that only 18% of people in England reported a high perception of heat risk. Approximately 30% said they knew little or nothing about the actions that could protect them. A similar proportion had encountered no heat alerts or heat-protection information at all, indicating that two different failures can occur: some people never receive a warning, while others receive one without understanding its relevance or knowing how to respond. The report also identifies uncertainty about the alerts themselves. Some respondents did not recognise what they were looking at, while others found the message difficult to interpret or were unclear about the practical steps expected of them. A warning may therefore fail before it becomes a decision, particularly when the language is abstract or does not connect the risk to everyday experiences such as sleeping in an overheated bedroom, travelling on public transport or caring for a family member.

“People aren’t ignoring these alerts because they don’t care,” said Dr Mehri Khosravi, a research fellow in behavioural change and risk communication at UNU-INWEH and lead author of the policy brief. “They read them and think, this isn’t about me.” Khosravi said heat continues to be perceived as good weather or as a threat limited to the very old and very ill. That perception can produce what risk researchers describe as a gap between hazard recognition and personal susceptibility. If people do not identify themselves as vulnerable, they are less likely to change routines, check on neighbours, drink more fluids, seek cooler environments or alter strenuous activity. The challenge is therefore not only to distribute technically accurate forecasts, but also to make the causal pathway from heat exposure to health effects visible and personally meaningful.

Interviews with professionals involved in England’s heat-risk system suggest that its communication architecture has been designed primarily for coordination among institutions. Among the practitioners interviewed, 76% identified informing the public as a communication objective, while substantially less emphasis was placed on motivating people to act or enabling them to do so. During a heatwave, alerts help national agencies, local authorities, health services and emergency responders coordinate their activities. That institutional function is essential, but it does not automatically translate into household-level protection. A message can move efficiently through government and health networks while failing to reach a person living alone, working outdoors, caring for an older relative or occupying a poorly ventilated home.

Digital communication has increased the speed and scale of heat warnings, but the report argues that speed should not be confused with equal access. Online platforms can distribute information rapidly, yet their reach depends on connectivity, digital confidence, language, trust and the habits of different age groups. Social media was identified as the least trusted source of heat information, particularly among older adults. The channels most heavily used by authorities may consequently be least effective for some of the people most exposed to harm. The researchers point to libraries, faith groups, voluntary organisations, social-care providers and other trusted intermediaries as ways to carry heat information into communities. These organisations can do more than repeat an alert: they can explain what it means, identify who may need help and connect general advice to the physical realities of local homes and neighbourhoods.

The report’s central argument is that heat resilience cannot be created by warnings alone. Housing conditions, deprivation, existing health problems and environmental exposure determine how much heat people experience and how effectively they can escape it. A warning cannot cool a top-floor flat that stores heat, provide shade in a treeless neighbourhood or repair a home with inadequate ventilation. The authors call for heat resilience to be incorporated into housing standards, planning policy and retrofit programmes, alongside stronger enforcement and implementation of Part O of England’s Building Regulations, which addresses overheating in residential buildings. They also recommend investment in local-authority and community capacity, because protective action often depends on organisations that know residents personally and can respond before a heatwave becomes a medical emergency.

“A warning tells you a heatwave is coming. It doesn’t tell you how to get through the night in a flat that traps heat,” said Professor Kaveh Madani, director of UNU-INWEH and a co-author of the policy brief. The researchers argue that future evaluation should measure whether alerts prompt protective behaviour rather than simply counting how many people saw them. That shift would treat communication as part of a technical intervention whose success can be tested through outcomes: whether people understand their personal risk, know what to do, can access a cooler place and receive support when they need it. England’s warning system may be effective at detecting and announcing dangerous heat, but the new findings suggest that the next stage of heat adaptation must move beyond notification. As extreme temperatures become a recurring public-health hazard, the decisive question will be whether warnings reach people in forms they trust—and whether the places where they live allow them to act.

News Publication Date: 14 August 2026

Web References: https://unu.edu/publication/strengthening-englands-heat-resilience-warnings-long-term-adaptation; https://unu.edu/inweh

References: Khosravi, M., Assan, A. and Madani, K. (2026). Strengthening England’s Heat Resilience: From Warnings to Long-Term Adaptation. United Nations University Institute for Water, Environment and Health. DOI: 10.53328/INP26PMK001. Support paper: Assan, A. A., Khosravi, F. and Osei, G. (2026). “The heat is on: Understanding public responses to heat-health alerts in England.” Energy Research & Social Science, 135, 104685.