South Korea issued its first-ever emergency heatwave alert on Sunday under a new warning system launched this year, advising people to halt outdoor activities and keep cool. The new warning system was introduced to better deal with a rising number of heatwaves in South Korea, which have become longer and more intense, officials said. An emergency alert is issued when areas experiencing a heatwave are forecast to hit perceived temperatures of 38°C or an actual temperature of 39°C for one...