Temperatures are expected to rise throughout the weekend, with a 60% risk of a heatwave being triggered for Monday and Tuesday next week. Daytime highs in London could reach 32 degrees C, falling away at night to no lower than 19 or 20 degrees C. For other areas, daytime temperatures could reach 29-30 degrees C, with night-time minima of 15-18 degrees C.

This has triggered Heatwave Plan alert level 2, which means the risk that high temperatures being reached in one of more regions on at least two consecutive days, and the intervening night, is 60 per cent. London, the East of England, South West, South East and the Midlands are the most likely to be affected.

This is an important stage for social and healthcare services who will be working to ensure readiness to reduce harm from a potential heatwave.

The heat is especially dangerous for the very young, older people or those with serious illnesses. In particular, it can make heart and respiratory problems worse. In extreme cases, excess heat can lead to heat stroke, which can be fatal.

A Department of Health spokesperson said:

Keeping the home as cool as possible during hot weather and remembering the needs of friends, relatives and neighbours who could be at risk is essential. The elderly and those who are ill, are particularly vulnerable during hot weather and the most oppressive conditions occur in our towns and cities.

Although ozone levels increase in hot weather, they drop in the evening. Windows should be kept shaded and closed when the temperature is hotter outside than inside. People with respiratory problems should stay inside during the hottest part of the day.

Advice on keeping healthy can be found on NHS Choices at www.nhs.uk; NHS direct on 0845 4647 or GPs if concerned about health symptoms.

People are advised to contact their local environmental health officer if they have concerns that their home is too hot for themselves or a vulnerable friend, neighbour or relative. Environmental health practitioners at local authorities can visit to inspect the condition of a home for hazards to health, including excess heat.

Top tips for coping during a heatwave include:

• Check up on friends, relatives and neighbours who may be less able to look after themselves.
• Shut and shade windows when it is hotter outside and open them for ventilation when it is cooler outside
• People with serious health problems (for example heart conditions), should avoid going out in the heat, especially between 11am and 3pm
• Drink cold drinks like water or fruit juice regularly and avoid tea, coffee and alcohol.
• Stay tuned to the weather forecast and plan ahead with supplies think of elderly neighbours who may need help with supplies.
• Keep plenty of water to hand and stay in the shade where possible
• Identify the coolest room in the house to use as a room to cool down or sleep in