Temperatures are expected to peak between Friday and Saturday as forecasters predict 35C in some places – albeit lower than record temperatures last month which peaked at more than 40C in some areas.
Temperatures are also expected to persist overnight, especially in closely-packed urban areas.
It is anticipated that those vulnerable to the heat will suffer from adverse health effects such as sunburn and heat exhaustion and that the wider population is also likely to be affected.
Additionally, there is a “high chance” of road, rail and air transport delays, says the Met Office, and those with long working days are predicted to suffer from welfare issues.
A heat wave would also mean that more people are likely to visit coastal areas, lakes, rivers and other water courses, leading to an increased risk of water and fire-related incidents.
In order to stay safe, the Met Office has recommended people should look out for vulnerable neighbours and loved ones, with older people who live alone and who have underlying health issues being at the most risk.
It is especially recommended to avoid the sun between 11am and 3pm as this is when the UV waves are at their strongest.
When indoors, it is then suggested to close curtains in rooms facing the sun to prevent them from getting too hot.
It is also important to remember to drink plenty of water – but avoid caffeine and alcohol – while avoiding physical exertion.