East of England Ambulance Service received almost 5,000 calls during last weekend's heatwave - over 1,000 calls more than the weekend two weeks ago.
The service, which covers Essex, along with Bedfordshire, Cambridgeshire, Hertfordshire, Norfolk and Suffolk received 4,972 calls over last weekend, where the temperature rose to 27 degrees in Chelmsford on Sunday.
This is compared to the weekend of June 29 and 30, when the service received 3,857 calls.
Despite receiving only one officially heat related call last weekend, due to the categories of the ambulance's 999 call system, calls to faints and collapses could also have been due to the hot weather.
Neil Storey, Director of Emergency Operations said: "Our ambulance crews can be very busy at this time of the year, attending calls from people who might have overdone it in the heat.
"The warmer weather is something we all take advantage of, and by following just a few simple precautions, people can enjoy the sun safely.
"People should ensure they have enough medication, and take the necessary precautions to prevent the effects of heat exposure."
East of England Ambulance Service has also given the public tips to stay well in warm weather:
- Shut windows and pull down the shades when it is hotter outside. If it's safe, open them for ventilation when it is cooler
- Keep rooms cool by using shades or reflective material outside the windows. If this isn't possible, use light-coloured curtains and keep them closed (metallic blinds and dark curtains can make the room hotter).
- Have cool baths or showers, and splash yourself with cool water.
- Drink cold drinks regularly, such as water and fruit juice. Avoid tea, coffee and alcohol.