Papillion, Neb. ? Methamphetamine may have impaired the judgment and ability of a young couple to feel the cold weather when they became lost in a snowstorm and died of hypothermia, authorities said Friday.

Michael Wamsley and Janelle Hornickel, both 20, had enough methamphetamine in their systems to create confusion, hallucinations, hot flashes and anxiety, said Dr. Henry Nipper, director of toxicology at Creighton University Medical Center in Omaha.

Investigators believe the couple died Jan. 5, the same day they called 911 more than five times from a cell phone trying to explain their pickup was stuck in the snow and they were lost in a rural area southwest of Omaha. The calls, however, had bounced off different cellular telephone towers, making it impossible to accurately trace their whereabouts.