The UK Health Security Agency (UKHSA) has issued a heat-health alert as the Met Office forecasts high temperatures for the coming days.
This is the first Level 2 heat-health alert of the year, with high temperatures expected across the Midlands and the south of the country later this week.
The alert, which comes into place at midnight on Thursday (June 16) until midnight on Saturday (June 18) covers the East Midlands, East of England, London, South East and South West regions.
Dr. Agostinho Sousa, head of extreme events and health protection at UKHSA, said:
"High temperatures are expected in some parts of the Midlands and the south on Friday (June 17).
"We want everyone to enjoy the hot weather safely when it arrives and be aware of good health advice for coping with warmer conditions.
"During periods of hot weather, it is especially important to keep checking on those who are most vulnerable, such as older people and those with heart or lung conditions.
"Make sure to look out for signs of heat exhaustion and follow our simple health advice to beat the heat."
Dan Rudman, deputy chief meteorologist at the Met Office, said:
"Temperatures will continue to rise as we go through the week, becoming well above average by Friday, when many parts of the southern half of the UK are likely to exceed 30° or even reach 34° in some places.
"This is the first spell of hot weather this year and it is unusual for temperature to exceed these values in June.
"Many areas will also see some warm nights with minimum temperatures expected to be in the high teens or even low 20s for some overnight."