A Hong Kong man collapsed on Tai Wan beach in Sai Kung due to heat stroke while hiking alone following a Very Hot Weather Warning signal on Wednesday afternoon.

At 3:30pm, a 26-year-old Hong Kong man surnamed Chiang was found completely soaked in sweat and lying unconscious in a bush by the beach by some other walkers, Headline Daily reported.

Chiang was sent by helicopter to the Pamela Youde Nethersole Eastern Hospital, where he remained in critical condition, Oriental Daily reported.

A preliminary police investigation showed that Chiang suffered heat exhaustion and then heat stroke after spending many hours walking in the sun.

According to Sing Tao Daily, at 4pm, the temperature topped 34 degrees Celsius, the highest temperature on record so far this year.