The hot weather is forecast to remain across the UK into next week as an NHS boss warned the health service was seeing near record levels of demand at A&E departments.
The Met Office has forecast temperatures in the high 20s, with some areas reaching into the 30s.
It comes as an NHS medical director said the heat had contributed to one of the “busiest days ever” in A&E departments across the country on Thursday.
Earlier this week, the Met Office extended its yellow heat warning until June 19, while several schools in East Sussex closed on Thursday due to water shortages.
Dan Stroud, spokesman for the Met Office, said conditions would become “increasingly humid and uncomfortable” over the weekend, especially in inner cities, with temperatures unlikely to drop below the 20s overnight.
NHS national medical director Professor Sir Stephen Powis added: “We know the warm weather has increased demand on services and this week we have seen one of our busiest days ever at A&E departments.
“As we move into what’s forecasted to be a very warm weekend, the heat and the impact of industrial action will continue across the country.
“NHS staff are working hard and prioritising urgent and emergency care, so as ever, use 999 in emergency and life-threatening situations and NHS 111 online for other health concerns.”
A UK Health Security Agency spokeswoman warned that the sustained heat could impact the health and social care sector.
She said: “If current forecasted temperatures are reached it is likely that there could be some impacts across the health and social care sector.
“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.
“If you have friends, family or neighbours who you know are more vulnerable to the effects of hot weather, it is important you check in on them and ensure they are aware of the forecasts and are following the necessary advice.”
