As Europe endures more frequent and severe heatwaves, a new study from the United Nations University exposes a troubling disconnect: many people in England receive official heat warnings but simply ignore them. The research, which surveyed over 1,000 adults and interviewed dozens of risk communicators, found that 41% of those who saw a heat-health alert took no protective action.
The findings come as repeated heatwaves across Western Europe strain water supplies, health systems, and economies. While the visible damage—dried landscapes, melted glaciers, and scorched forests—is stark, the hidden toll on human health is equally alarming.
Why warnings fall flat
The study, led by experts at the United Nations University's Institute for Environment and Human Security, identified a clear gap between awareness and action. Only 18.1% of respondents perceived extreme heat as a high personal risk. Among those who saw an alert but did nothing, 19% cited low personal risk perception, 9% didn't recognize the alert, 7% were unsure what to do, and 5% found the message confusing.
“Simply sending out an alert is not enough,” the researchers concluded. “People need to understand that extreme heat can pose a risk to their health, recognise when a warning applies to them, and know what they can do to protect themselves.”
The study also found that 30% of respondents had never encountered any heat-health alert or protective information at all. This is particularly worrying because the most vulnerable—older adults, those with pre-existing conditions, and people in deprived areas—are often the least likely to receive digital warnings.
Digital channels miss the most vulnerable
Ninety percent of heat-risk communicators said they relied on digital channels, including social media. Yet social media was the least trusted source of heat information, especially among older adults. The researchers argue that authorities need to diversify their outreach, using trusted local organisations such as community groups, libraries, social care providers, voluntary bodies, and faith groups to reach those who are missed online.
“The channels used to communicate heat risks do not always reach the people who are most vulnerable to them,” the study warns.
Beyond warnings: structural change needed
The study also criticises the current approach to heat communication in England, which focuses on coordination between institutions and emergency preparedness rather than on changing individual behaviour. Informing people is the dominant objective, but information alone rarely motivates action.
Moreover, communication cannot address the underlying factors that make people vulnerable: poor housing, socioeconomic disadvantage, existing health problems, and limited access to resources. The researchers call for heat resilience to be integrated into housing standards, planning policies, and retrofit programmes, with stronger enforcement of measures to reduce overheating in buildings.
“The challenge is not just to warn people that the next heatwave is coming—but to make sure fewer people are vulnerable when it arrives,” they said.
As heatwaves become more frequent and severe, the study's authors urge England—and by extension other European countries—to move beyond a warning-based approach. They recommend that authorities measure the effectiveness of their communication not by website visits or social media engagement, but by whether people understand the warnings and take protective action.
The findings echo broader concerns across the continent, where tourist guides and health officials are demanding more robust responses to deadly heat. While some countries have introduced heat-health action plans, the gap between warning and action remains a persistent challenge.
For now, the study serves as a stark reminder that effective heat risk communication is not just about issuing alerts—it's about ensuring they lead to meaningful protection for those most at risk.
