The family of a retired doctor are searching for him after he fell while hiking in the Pyrenees mountains.
Tom Doherty, 67, from St Albans in Hertfordshire, was travelling and camping solo in southern France.
His son, Ricardo Zamora, said Mr Doherty fell on Tuesday at about 16:00 BST but managed to send two WhatsApp messages back to his family the UK alerting them.
Mr Doherty’s car was found near the Col d’Escots hiking trail in the Ariege region near Cirque de Gerac.
It is not known at this stage how seriously Mr Doherty was injured.
Members of his family have flown out to join the search and rescue efforts.
Mr Doherty previously worked as a consultant at the Hospital for Tropical Diseases in London.
