A man found dead outside a Rochester, Minn., home early Sunday may have succumbed to bitterly cold temperatures, although authorities are awaiting autopsy results before confirming the nature of Ali Gombo's death.

The 22-year-old Rochester man was found on the back deck of his sister's house, where he had been living, according to police. Authorities said Gombo was dropped off near the house early Sunday. He did not have keys to the residence.

Evidence at the scene suggested that he went to several doors and windows of the house in an attempt to get someone's attention. He apparently went to a neighbor's house and knocked on their door as well.

A neighbor spotted the body and called police shortly after 10 a.m. Sunday. Gombo was found without his shirt on. People sometimes undress in the late stages of hypothermia.

His death is not being regarded as suspicious, police said.

Temperatures in Rochester plunged to 15 degrees below zero early Sunday, with wind speeds up to 29 miles an hour.