Public health authorities warn of risks to older adults and vulnerable populations as parts of England brace for rising temperatures.
The UK Health Security Agency (UKHSA) has issued the country’s first yellow heat-health alert of the year, warning that even moderately high temperatures could pose significant health risks to vulnerable individuals. The alert, in force from 9pm on Thursday 12 June to 8am on Saturday 15 June, applies to the East of England, East Midlands, London and the South East.
According to the Met Office, temperatures are expected to peak at 30°C on Friday — a level that, while not extreme for the wider population, could seriously affect older adults and those with pre-existing conditions, particularly cardiovascular and respiratory diseases.

“Our findings show that even moderate heat can result in serious health outcomes, especially for older adults. It is therefore important that everyone takes sensible precautions while enjoying the sun.”
Dr Agostinho Sousa, senior official, UKHSA
The UKHSA has urged the public, health services and social care providers to remain vigilant and make necessary preparations as summer begins to intensify. The heat-health alert system, operated jointly by UKHSA and the Met Office, categorises risks using a colour scale from green to red. A yellow alert signals that increased strain on health services is expected and that vulnerable groups face an elevated risk of health complications.
Speaking about the warning, Dr Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, said:
“Our findings show that even moderate heat can result in serious health outcomes, especially for older adults. It is therefore important that everyone takes sensible precautions while enjoying the sun.”
He added that the forecasted spike in temperatures may be brief but could still lead to serious consequences:
“The forecasted high temperatures are expected to be short-lived but could primarily impact those over the age of 65 or those with pre-existing health conditions. If you have friends, family or neighbours who are more vulnerable, it is important to check in on them and ensure they are aware of the forecasts and are following the necessary advice.”
The warning comes as the UK transitions into warmer months, prompting the UKHSA to remind care homes, hospitals and community services to be on alert for similar conditions through the summer.
To protect against heat-related illness, UKHSA has advised the public to take several basic but essential steps:
- Keep living spaces cool by closing curtains and windows during the hottest parts of the day.
- Stay hydrated and avoid alcohol.
- Avoid outdoor physical activities during peak heat hours, typically between 11am and 3pm.
- When outside, wear light, loose-fitting clothing, use sunscreen regularly, and stay in shaded areas when possible.
- Be aware of the signs of heat exhaustion and heatstroke, including dizziness, headaches, excessive sweating and nausea.
The agency has made real-time updates available through its online dashboard and issued a public blog detailing how extreme temperatures affect the body and what can be done to avoid negative outcomes.
The heat-health warning arrives amid a backdrop of increasing awareness around climate change and its impact on public health. While the UK has so far been spared the more extreme heatwaves seen in mainland Europe, recent summers have demonstrated how ill-prepared infrastructure and services can quickly become overwhelmed.
This week’s yellow alert serves as an early test of preparedness — both for authorities and the public — ahead of what could be another summer of unpredictable weather extremes. Authorities continue to monitor conditions closely and may escalate the alert if temperatures persist or rise further.
With the summer solstice still a week away, experts say this may only be the beginning of what could be a particularly challenging season for public health management.