The 41-year-old man was discovered on Monday when workers detected an unusually high temperature in the freezer and realized the hatch was not securely fastened.
"A morgue manager opened the hatch, saw two people lying inside, felt scared enough to yell out and then even cried," the Liberty Times reported. "She didn't stabilize for a long time."
The man took a drug before entering the freezer to speed what appeared to be suicide attempt, local papers said. They said his girlfriend died on Friday from an overdose of sleeping pills.
The morgue would step up security to ensure that family and others who come by to identify bodies do not stay too long, morgue administrator Chang Lung-ching said.