Mechanics were straightening a ladder on the derrick in the shop using an acetylene torch and a 10-ton hydraulic jack. As the mechanics were extending the jack to straighten out the ladder, the cylinder on the jack was turning and the quick-connect fitting ended up against the footrail of the derrick. This caused the nipple to break and a mist of oil was released from the jack. The oil mist ignited resulting in a flash fire. The injured employee sustained second- to third-degree burns burns to the right hand, the left cheek, and the left side of their neck as well as burns to both arms. The employee was hospitalized.