A rare case of Legionnaires' disease has been confirmed sparking a multi-agency investigation.
The patient is being treated in Aberdeen Royal Infirmary (ARI) for the potentially fatal illness.
NHS Lanarkshire said the patient, who lives in its health board area, became ill while on Shetland where they work, after staying a night in Aberdeen on the way there. The patient was then taken to ARI for treatment.
NHS Lanarkshire is working with North Lanarkshire Council, NHS Grampian, NHS Shetland and Health Protection Scotland to investigate the possible source of the infection.
Legionnaires' disease is transmitted by aerosol spread - that is, by inhalation of infected water droplets.
Dr David Cromie, consultant in public health medicine at NHS Lanarkshire, said: "We are currently carrying out an investigation to identify the source of the Legionella infection.
"Often with single cases of Legionella, it can be difficult to positively identify the source of the bacteria, however we are currently investigating a number of possible sources, although to date no source of infection has been identified.
"You cannot catch Legionnaires' disease from an infected person as it does not spread from person to person. Most people exposed to Legionella do not become ill.
"People catch Legionnaires' disease by inhaling small droplets of water suspended in the air, which contain the bacteria. You cannot catch Legionnaires' disease from drinking water."
The bacteria which cause Legionnaires' disease is common in the environment but illness only occurs if water containing the bacteria becomes an aerosol and is inhaled.
Sources of infection include air conditioning systems, cooling towers, spa and jacuzzi baths. NHS Lanarkshire has not yet said when the patient became ill.