While preparing coffee service in the aft galley, the C flight attendant (FA) observed the coffee maker emitting an unusual noise and coffee was pooling on the burner. The FA lifted the potlocking lever on the coffee pot and hot coffee and coffee grounds erupted onto her face, neck, and chest. The flight diverted and landed at Nashville International Airport, Nashville, Tennessee where medical personnel met the flight at the gate. The FA was transported to the hospital and diagnosed with second-degree burns. In January of 2013, the Federal Aviation Administration issued Safety Alert For Operators (SAFO) 13001, which addressed reported cases of coffee filter packages bursting in flight during coffee preparation, resulting in 1st and 2nd degree burns to flight attendants and bystanders. The SAFO encouraged air carriers and operators to add cautionary instructions and procedures to the Flight Attendant Manual (FAM) and training program, warning crew members of the dangers to personnel and equipment.