Health experts are urging people to take action straight away in order to keep cool, as scorching temperatures are forecast for the bank holiday weekend.
A Hot Weather Alert Level 3 in the East of England has been declared by the Met Office from 9am on Saturday until 9am on Monday.
The warning say that there's a 90% probability of temperatures being high enough on at least two consecutive days in Cambridgeshire.
A Level 3 alert means that it's forecasted to be exceptionally hot and sunny over the coming days in the county and temperatures are expected to exceed 30C in many areas - with warm temperatures and humid conditions to continue overnight.
Val Thomas, consultant in public health at Cambridgeshire County Council, said: "While hot weather is enjoyable for most people, for some it is challenging. High temperatures can be very uncomfortable and affect the health of the young and older people. It can also worsen the condition of those with an ongoing health condition, especially for those with heart and lung problems.
"As the heatwave arrives in Cambridgeshire, we're asking people be alert and look out for those at risk from high temperatures.
"If you see someone feeling dizzy, weak, anxious or have intense thirst and headache, move them to a cool place as soon as possible and give them some water or juice to rehydrate and cool down - if their symptoms continue, seek further medical advice from your pharmacist or doctor."
Here are some practical tips on how to stay cool and cope with the hot weather:
- Look out for others, especially older people, young children and babies and those with underlying health conditions
- Shade or cover windows that are exposed to direct sunlight during the day, and open windows at night when the temperature has dropped
- Drink plenty of water as sugary, alcoholic and caffeinated drinks, including tea and coffee, can make you more dehydrated
- Never leave anyone in a closed, parked vehicle, especially infants, young children or animals
- Try to keep out of the sun between 11am to 3pm
- Walk in the shade, apply sunscreen and wear a hat, if you have to go out in the heat
- Avoid physical exertion in the hottest parts of the day
- Wear light, loose fitting cotton clothes
- Make sure you take water with you if you are travelling