A traffic policeman in Udon Thani was first on the scene after a report came in from a distraught Thai wife that her foreign husband had collapsed in the family car in a bank car park.
Sen Sgt-Maj Charoen Janrak found Mr Melvin, an 81 year old American man, slumped in a green four door Mazda pick-up.
With the help of bank staff they got the man out of the pick-up and used a defibrillator then CPR for twenty minutes before medics of the North Eastern Wattana Hospital arrived, reported Sanook.
He was pronounced dead at the hospital at 3pm.
Mr Melvin's Thai wife said they had been married for 40 years and he had no known illnesses. They had gone to the bank to visit an ATM and her husband had waited for her in the car.
He is believed to have suffered a heart attack.