Temperatures hit record highs for May in the United Kingdom and France on Monday, as forecasters warned of a prolonged period of extreme heat across Europe throughout the week.A so-called heat dome of warm air from northern Africa trapped under a high-pressure system over western Europe is behind the high temperatures not usually seen until high summer.Temperatures in Spain were expected to peak later this week at 38 degrees Celsius (100 degrees Fahrenheit), while parts of Italy imposed...