Hong Kong has issued its first “very hot weather” warning of the year, with the city expected to endure a heatwave through Friday. The Hong Kong Observatory (HKO) issued the warning at 7.45am on Tuesday, with the mercury expected to reach 35 degrees Celsius. A man is running in Hong Kong ‘s public space File photo: Kyle Lam/HKFP. The warning is triggered when the mercury is set to reach, or exceed, 33 degrees Celsius. As of around 1:30pm on Tues…