Europe is sweltering under an unusually early blast of heat, with forecasters warning that a powerful "heat dome" is driving temperatures far beyond what is typical for this point in the year. The surge came after a record-setting Monday, when France registered its hottest May day ever recorded, according to the national weather agency, while the UK also hit unprecedented highs. Meteorologists say the spike is being fuelled by a mass of hot air from northern Africa, trapped beneath a high-pressure system over western Europe…