First heat health impact reports reveal higher illness and death among vulnerable groups in Wales

The first-ever heat health impact reports published in Wales have revealed a clear link between extreme heat and rising illness and death rates, particularly among vulnerable groups such as older adults, children, and people from deprived communities.

The findings, released by Public Health Wales, show that even short periods of intense heat can have a measurable effect on public health, increasing hospital attendances, emergency calls, and overall mortality rates.

The reports also warn that climate change is likely to make such events more frequent, longer, and more dangerous in the years ahead.

Researchers found that “heat events”, including heatwaves, hot nights, and cumulative periods of sustained warmth, were strongly associated with increases in both morbidity and mortality.

The analysis showed that the health impacts of high temperatures were often amplified by factors such as air pollution and humidity.

During the warmest periods of summer 2024, there was an 83% rise in children attending A&E for gastrointestinal problems, a 90% increase in psychological and psychiatric attendances in urban areas, and a noticeable rise in 999 calls for people suffering from fitting. GP consultations for heatstroke also increased across Wales.

Even in the absence of a national heatwave, the reports found that a brief heat period between 28 July and 2 August 2024 led to a statistically significant increase in daily deaths, particularly among older adults and people living in cities. The mean daily mortality rose to 93 deaths during the heat period, compared with 84 deaths outside it.

While further research is needed to confirm that heat directly caused the rise in deaths, experts say the findings underline the urgent need to prepare for a warming climate.

The three interim reports were produced by the Integrated Climate and Environmental (ICE) Surveillance Team, part of Public Health Wales’s Communicable Disease Surveillance Centre (CDSC). Their aim is to identify which heat exposures pose the greatest health risks and to build an evidence base to help shape future public health planning.

Wales has experienced its ten hottest years on record since the early 2000s, and climate models suggest temperatures will continue to climb.

Pressure

Public Health Wales warns that more frequent and prolonged heat events could place growing pressure on health and social care services unless action is taken to strengthen surveillance and prevention measures.

Dr Behrooz Behbod, Consultant Epidemiologist at Public Health Wales, said the research highlights the importance of building resilience now.

“As the climate warms globally, heat events will be more frequent and are likely to cause more health-related impacts,” he said.
“By measuring the impact specifically on health and care services in Wales, we can plan more effectively and build greater resilience for the future.”

Dr Behbod added that other countries such as France, the United States, and Australia have already developed advanced heat-health monitoring systems, and Wales can learn from their experience in adapting to a changing climate.