An FDNY supervisor’s department SUV was stolen as it was left running outside a Bronx hospital.

But the crooks weren’t hard to find — they were caught sitting in the vehicle, which is typically fire-engine red with “FDNY” written on it, according to authorities.

The engine had been left running as the FDNY personnel were inside Jacobi Medical Center at around 10 p.m. Saturday before the suspects got in and drove away, police said.

The FDNY supervisor alerted police, who began tracking the vehicle’s GPS system.

The vehicle — and two suspects inside it — was found a short time later about five miles away, sitting along Randall Avenue in front of the Soundview Houses.

Police arrested Joshua Gilead, 31, and Jorge Santiago, 54, and charged them with grand larceny, petit larceny, unauthorized use of a stolen vehicle and possession of stolen property.