NEW CASTLE, Del. (AP) — A Delaware worker who passed out inside a chemical tank that he had been cleaning has been rescued.

Holloway Terrace Fire Department Chief Mark Willis tells news outlets that his department and a dozen other units responded to the Port of Wilmington Tank Wash on Monday for reports of a person collapsed inside a tractor-trailer tank.

Willis says the man's collapse is believed to be heat-related. Paramedics said the man tried to remove himself from the tanker after he became dizzy, but fell and collapsed.

Willis says the substance he was cleaning "posed no inhalation hazard."

The man was semi-conscious when he was removed from the tank by a harness-and-pulley system. He was hospitalized for neck and back pain, as well as the heat-related emergency. His current condition is unknown.