By James Davey and Richa Naidu LONDON (Reuters) – Sales of electric fans, hoses, air conditioning units and sprinklers are soaring as Britons swelter amid record temperatures, retailers said. Britain was braced for temperatures to hit 40C (104 degrees Fahrenheit) for the first time this week, with ministers urging the public to stay at home as the heatwave caused train services to be cancelled, one London airport to shut its runway and some schools to close. Sainsbury’s, Britain’s No. 2 supermarket group which also owns the Argos general merchandise business, said sales of fans last week rose …