The UK Health Security Agency (UKHSA) and the Met Office have issued a first heat-health alert of the year.
Six regions in England have been included in the yellow alert, including the West Midlands.
The alert is currently in place from 9am on Friday to 9am on Monday, and if forecast temperatures are reached there could be an impact on the health and social care sector.
Temperatures are predicted to hit around 30C.
Under the new heat-health alert (HHA) 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 over-65s or those with pre-existing health conditions, including respiratory and cardiovascular diseases.
There is also the potential for indoor environments, including health and care settings, to become very warm.
Dr Agostinho Sousa, head of extreme events and health protection at UKHSA, said: "In the coming days we are likely to experience our first sustained period of hot weather of the year so far, so it’s important that everyone ensures they keep hydrated and cool while enjoying the sun.
"Forecasted temperatures this week will primarily impact those over the age of 65 or those with pre-existing health conditions such as 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."
The Government alert has issued the following steps to stay safe during the hot weather:
Check on family, friends and neighbours who may be at higher risk of becoming unwell, and if you are at higher risk, ask them to do the same for you
Know the symptoms of heat exhaustion and heatstroke and what to do if you or someone else has them
Keep out of the sun at the hottest part of the day, between 11am and 3pm
If you are going to do a physical activity (for example, exercise or walking the dog), plan to do these during times of the day when it is cooler such as the morning or evening
Keep 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, seek shade and apply sunscreen regularly
Drink plenty of fluids and limit your alcohol intake
Dan Harris, deputy chief meteorologist at the Met Office, said: "Temperatures will rise later this week and into the weekend, with a plume of warm air being drawn in from the south.
"Temperatures over the weekend could peak around 30C in some parts of England and remain well above average overnight through the weekend.
"Coupled with the rise in temperatures is an increase in the likelihood of some potentially heavy and thundery showers, which could bring some localised disruption for some from late on Friday and into the weekend, though it is not possible to be definitive about exact details this far from the potential event."