SAN FRANCISCO (AP) — Hundreds of volunteers and officials using drones, aircraft, and off-road vehicles are searching for a man who went for a run in the San Francisco Bay Area and didn’t return home.

Philip Kreycik left his Berkeley home Saturday morning and drove to the Pleasanton hills to go for a one-hour run. When he didn’t return home by the afternoon, his wife called the authorities.

KGO-TV reports crews worked into the nighttime hours Monday evening using a heat-sensing drone, equipped with high-tech cameras to try and find the 37-year-old husband and father of two.