People urged not to light barbecues, campfires or anything else that could spark fire during period of extreme heatMillions of people across England and Wales received an emergency alert to their phones on Friday as the government warned against activities that could start fires.The deputy prime minister, Louise Haigh, said it was the most extensive use to date of the emergency alert system, with phones beaming a siren noise about 7pm, with the warning: “There is a serious risk of wildfires na