Met Office puts UK on heatwave alert as temperatures soar to 32C Racegoers at York enjoying the sunshine. Photograph: Ed Sykes/Action Images Parts of Britain have been issued with an official level-three heatwave alert, one below the highest classification of emergency, as health officials sounded fresh warnings over the bout of "dangerous" weather. Public health authorities said the elderly and those suffering long-term illnesses were particularly vulnerable, as Britain swelters in temperatures hotter than in parts of the Caribbean. The warnings came as England and Wales recorded the hottest day of the year so far. Temperatures reached 32C in south-east England, with much of the UK experiencing between 28C and 31C. Forecasters said the hot weather shows little sign of abating, with temperatures remaining in the mid- to high-20s for much of this week. The region where people's health is deemed to be most at risk is Yorkshire and the Humber, with the Met Office on Saturday imposing a level-three alert for the region. Across most of England, level-two alerts are in place, with advice to the public on preparing for a heatwave. "Heatwaves can be dangerous, especially for the very young, very old or those with chronic diseases," the Met Office said. A spokesman for Public Health England (PHE) added: "Level-two alerts are triggered as soon as the Met Office forecasts that there is a 60% chance of temperatures being high enough on at least two consecutive days to have a significant effect on health. The alert will normally be issued two to three days before a heatwave is expected. As most deaths occur during the first two days, this is an important stage at which to ensure readiness and swift action to reduce harm from a potential heatwave. Dr Angie Bone, head of PHE's heatwave plan, said: "The elderly and those with long-term illnesses are particularly vulnerable to the effects of very hot weather, so it's important to look out for them." Meanwhile, the RAC said more than 11 million motorists were planning to hit the road this weekend, and that the most popular destinations would be the Lake District, Devon and Cornwall, the south coast of England and Yorkshire. Retailers said the weather had had a profound impact on the sales of certain products, particularly as customers plan barbecues and parties. Tesco predicted that sales of sausages alone will hit 9m over the weekend.