A British man, 80, was found on the side of a Valencia Province highway in a cold and disorientated state.
The discovery was made in the early hours of December 15 but details were only released recently.
A motorist told a Guardia Civil patrol that he spotted a mysterious-looking bulge at the side of the N-332 at kilometre point 220.
Several officers drove to the area and found a man slumped next to the barrier.
Temperatures at the time were just four degrees and he showed clear signs of hypothermia and disorientation.
He could barely speak as his lips had gone purple and his face was numb.
Officers were able to identify him as an 80-year-old British man who walked out of a hospital without staff noticing he had gone missing.
An ambulance took him to Gandia Hospital accompanied by some of the Guardia officers.
No further information has been released by authorities.