A sick walker had to be rescued after drinking water on the West Highland Way thought to have been contaminated.
The incident on Tuesday was the second time in less than a week that a hiker had fallen ill on the popular long distance trail and needed assistance.
Lomond Mountain Rescue Team has now issued a warning to other walkers about safe water consumption.
It said: “Given this is the second incident in under a week where contaminated water may have been a contributing factor, we would repeat the guidance that in the first instance water should be obtained from known sources.
“We don’t want to be alarmist but we also want all walkers on the West Highland Way to enjoy the hike and stay fit and healthy.”
Walkers have been advised to avoid drinking from rivers, burns, or streams – especially on the approach to Conic Hill where livestock and run-off can contaminate sources.
Rescuers were first called to assist an incapacitated walker just south of Rowchoish Bothy last Wednesday morning.
Lomond MRT said the person had been vomiting since around 9pm the night before.
The team was then called by Police Scotland on Tuesday afternoon to help another walker just north of the camping management zone at Rowardennan.
Rescuers said the walker had been vomiting since Monday evening and was unable to walk when they were found.
After a short search, the walker was located and assessed before being transported back to the main car park at Rowardennan in a team vehicle.
On the first incident, Lomond MRT said: “With the official West Highland Way season well under way, we would take the opportunity to highlight the importance of being well fuelled and hydrated, especially on the section north of Rowardennan where resupply is limited.”
Walkers are advised to use Scottish Water fountains, taps marked or known to be drinking water, or bottled water while they are on the West Highland Way.
“If water is collected from a stream, it should be treated prior to consumption,” the team said.
“Please bear in mind that filtering alone may not guarantee safety and we would recommend secondary treatment such as boiling or chemical treatment.
“This is especially suggested in areas where livestock/run-off may be an issue, eg on the approach to Conic Hill.”