The Met Office has issued a level 3 amber alert for the East Midlands with the heatwave set to return.
Temperatures had cooled over the last few days but the warm weather is due to come back this week.
The Met Office says there is a 90 per cent probability of heatwave conditions between 9am on Monday and 9am on Friday in parts of England.
It states: "Long spells of sunshine, will develop with temperatures generally ranging from very warm in West and East Midlands, to hot and humid, locally very hot in east and southeastern areas.
"Away from northern England, dry and sunny weather should dominate through the week, but interspersed with heavy showers in afternoon and evening periods. Temperatures will be very warm or hot, locally very hot in the east.
"Thresholds could be breached in places from Monday onwards, with very warm and muggy overnight conditions."
Advice from the Met Office includes:
* Stay out of the sun
* Keep your home as cool as possible - shading windows and shutting them during the day may help. Open them when it is cooler at night.
* Keep drinking fluids
* If there is anyone you know who may be at risk, for example an older person living on their own, make sure they know what to do.
The level 3 warning, one behind a national emergency, has been issued with temperatures set to be in the high 20s this week.
Alerts are issued when the Met Office forecasts that certain heat thresholds will be passed. The aim is to alert health professionals so they can take action to minimise the impact of the heat on people's health.