Over the past month, the country has been enjoying some high temperatures that make a welcome change to the usual drizzle of a British summer. But heatwaves aren’t just about ice cream for lunch and trips to the outdoor pool – they can have a very serious impact.

Following the declaration of a “national emergency” and the first ever red extreme heat warning last month, the Met Office has once again issued a health precaution as it prepares for temperatures to reach up to 35°C in some areas this week.

The warning applies to southern and central England, as well as parts of Wales from Thursday until Sunday as the country braces for yet another heatwave.

Previously, the Met Office’s highest warning means meant that there was a risk to life as temperatures hit up to 40°C.

The lower amber warning “requires social and healthcare services to target specific actions at high-risk groups,” such as the young, elderly, disabled and homeless. Amid the driest July since 1935, warnings of the threat posed by wildfires have been issued, with fire services urging people not to light bonfires or barbecues, or let off fireworks or sky lanterns.

People in the UK are used to treating hot weather as a “chance to go and play in the sun” but “this is not that sort of weather”, said Met Office CEO Penny Endersby. However, heatwaves bring with them a risk of heat stress and heat stroke, which occurs when the body’s means of controlling its internal temperature starts to fail.

According to the Health and Safety Executive, typical symptoms include:

• an inability to concentrate
• muscle cramps
• heat rash
• severe thirst - a late symptom of heat stress
• fainting
• heat exhaustion – fatigue, giddiness, nausea, headache, moist skin
• heat stroke – hot dry skin, confusion, convulsions and eventual loss of consciousness. This is the most severe disorder and can result in death if not detected at an early stage

The heatwave, which originated in north Africa, has slowly been spreading across Europe and has fuelled wildfires in Portugal, France and Spain.

Images: Getty