Search Intensifies for Missing Hiker on Colorado's Longs Peak

Lucas Macaj, 23, last communicated from the summit on Sunday before severe weather hit the area.

Authorities are using air reconnaissance, infrared technology, and ground teams in the search effort.
Macaj's car was found at the Longs Peak Trailhead, but he has not been seen since his last text.
Strong winds, whiteout conditions, and low visibility have hampered search efforts.
Macaj is described as 5'9", 155 lbs, with brown hair and green eyes, and wearing dark hiking gear.
The Keyhole Route, which Macaj took, is a challenging climb with winter-like conditions year-round.