Britain's fourth heatwave of summer began today and could last for at least a week as temperatures hit 34C and 'tropical nights' make sleeping uncomfortable. The country is also on alert for wildfires after a major incident in Dorset where 100 firefighters battled a blaze that ravaged hundreds of acres of land at the weekend. Crews battling the blaze at Holt Heath near Wimborne captured a rare 'dust devil' on camera – a whirlwind of dirt which normally occurs in the desert or other arid areas. #weather #ukweather #heatwave #tornado #dustdevil #wildfire #metoffice #news