Heat-health alerts are issued by the Met Office and UK Health and Security Agency (UKHSA) when the country is expecting high or low temperatures that could have an impact on health.

Dr Agostinho Sousa, head of extreme events and health protection at UKHSA, explained: “Our heat-health alerting system plays a vital role in notifying professionals and the public of forecasted high temperatures that can affect the health of those most at risk, particularly individuals over the age of 65 and those with pre-existing health conditions.

“Last year saw record high temperatures across England and evidence shows that heatwaves are likely to occur more often, be more intense and last longer in the years and decades ahead. It is important we are able to quantify the likely impacts of these heatwaves before they arrive to prevent illness and reduce the number of deaths.

“We look forward to collaborating with the Met Office to provide evidence-based advice to professionals and the public, to ensure they are well-equipped to respond to these events.”

Will Lang, Head of Situational Awareness at the Met Office, added: ”The updated health alerts will be complementary to, and run alongside our National Severe Weather Warnings, and will play a pivotal role in helping save lives, protect property and the economy as we all work to tackle adverse weather and climate change going forward.

“It is only by working in close partnership with organisations like UKHSA that effective action can be taken when it matters.”

But what do the alerts mean?

What is a yellow cold-health alert?

A yellow alert means that any impacts include the increased use of health care services by vulnerable populations and an increase in risk to health for individuals over the age of 65, those with pre-existing health conditions, including respiratory and cardiovascular diseases and some other vulnerable groups, such as those sleeping rough.

What is an amber heat health alert?

An amber alert means that weather impacts are likely to be felt across the whole health service for an extended period of time, with potential for the whole population to be at risk and where other sectors may also start to observe impacts, indicating a coordinated response is required.

What is a red heat health alert?

A red heat health alert indicates significant risk to life for even the healthy population. In the case of a red alert, severe impacts would be expected across all sectors with a coordinated response essential.