According to a tweet posted by the Harris County Sheriff's Office, the 60-year-old man was found dead just before noon at I-10 East and Sheldon Road.
Though a formal cause of death has not been determined, the sheriff's office said he died "possibly of exposure."
"[A] cause of death will be determined by autopsy," read the tweet.
In a second tweet, the sheriff's office said members of its homeless outreach team offered to take the man to warming center before, but he "unfortunately declined."
The unusually icy emergency knocked out power for millions of Texans. Many have been hunkering down at various Houston shelters, but Mayor Sylvester Turner said other warming centers had to be shut down because those locations, too, lost power.
READ ALSO: Warming stations and shelters open throughout the Houston area
George R. Brown Convention Center provides warm shelter
The Associated Press contributed to this report.