Mountain rescue experts were deployed on Monday evening after a walker got lost in the fog.
Donegal Mountain Rescue Team were tasked at 6.49pm to assist a walker who had become lost on Sliabh Liag due to poor visibility caused by fog.
The walker was located using SARLOC technology - an app designed to allow people to accurately give their locatio even when lost.
A hill party made their way to the walker, while the remainder of the team was put on standby.
After finding the casualty and assessing their condition, the team set up a storm shelter and provided the casualty with warm drinks, food, and extra clothing.
The casualty was safely walked off the hill, and assessed by the National Ambulance Service. An Garda Síochána then assisted the casualty in getting back to their car.
The serach and rescue team was stood down at 2.45am