A heatwave occurs when the average temperature is unusually hot for three or more days in a row. That's compared to past weather data taken from the same location
A relentless heatwave swept across Europe, breaking temperature records in several countries, disrupting transport, straining hospitals and triggering health alerts. Scientists said the extreme conditions were intensified by climate change, with authorities warning of further risks as the scorching weather spread eastward
News of a likely second year of record heat comes a day after Republican Donald Trump, who called climate change a "hoax" and promised to boost oil drilling and production