A forecast of temperatures up to 30C on Friday for parts of England has triggered the first yellow heat-health alert of the year. Issued by the UK Health Security Agency, the alert warns health and social care services to prepare for a possible rise in people needing help. A yellow warning is issued for periods of heat that are unlikely to impact most people but could affect those who are particularly vulnerable, including over 65s and those with lung or heart conditions.

Dr Agostinho Sousa, head of extreme events and health protection at UKHSA, said: “Our findings shows that even moderate heat can result in serious health outcomes, especially for older adults, and it is therefore important that everyone takes sensible precautions while enjoying the sun.

“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.”

The alert was put in place from 9pm on Thursday, 12 June to 8am on Sunday, 15 June and covers the East of England, East Midlands, London and South East regions of the country.

The UKHSA urged people to stay safe by doing the following:

• knowing the symptoms of heat exhaustion and heatstroke and what to do if you or someone else has them
• keeping your home cool by closing windows and curtains in rooms that face the sun
• if you do go outside, cover up with suitable clothing, such as an appropriate hat and sunglasses, and seek shade and apply sunscreen regularly
• keeping out of the sun at the hottest time of the day, between 11am and 3pm
• if you are going to do a physical activity (for example, exercising or walking the dog), plan to do these during times of the day when it is cooler, such as the morning or evening

Dr Sousa added: “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 UKHSA works with the Met Office to carry out risk assessments and issue the alerts.

Amber alerts are used when there is potential for the whole population to be at his,

And a red alert indicates significant risk to life for even the health population.