Health and weather watchdogs have extended heat health alerts covering the country, including Twickenham, through to 9am next Monday.

The yellow alert means that while the temperatures will be bearable for most, they may cause problems for some elderly and medically vulnerable people.

A yellow alert is below the 'amber alert' with is high temperatures and thunderstorms that were seen through the weekend and into Monday.

Under the new Heat-Health Alert system introduced by UKHSA and the Met Office, 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 or those with pre-existing health conditions, including respiratory and cardiovascular diseases.

The NHS added a warning that its services in the area are under strain with high temperatures combining with raised air pollution.

It said: "Hospital services across South West London are currently very busy due to extreme heat, pollution and pollen levels. We're seeing high numbers of people coming in with breathing difficulties and older people who are dehydrated.

"If you, or your child, has asthma or other respiratory conditions – keep taking your regular preventer inhaler and stay indoors wherever possible, keeping windows and doors closed as much as possible. If you do need to go outside, shower and change your clothes to wash pollen off.

"Older people are particularly at risk of becoming unwell during a heatwave. Drinking water and staying out of the sun are most important for staying well – more tips are below.

"The NHS is still here for people who need care. If you need medical help or advice to please go to 111.nhs.uk first, unless it is a life-threatening emergency in which case, call 999."