A 30-year-old man was flown to hospital after collapsing and losing consciousness while visiting Crescent Island as one of a group of 24 people on 26 September.
Police received a report at about 1pm after the man had reportedly felt dizzy and unwell before becoming unconscious, Star Headline reported.
The Government Flying Service sent a helicopter to the island and took him to Pamela Youde Nethersole Eastern Hospital for emergency treatment.
The incident occurred while the Hong Kong Observatory’s Very Hot Weather Warning was in force. The warning had been issued at 6.45am that morning.
The cause of the collapse remained under investigation.