The flight instructor reported that the student pilot was receiving flight instruction in preparation for a helicopter hover endorsement. The flight instructor and student pilot planned to practice hovers with pedal turns to experience wind effect from varying directions. The winds at the time were about 12 kts from the south. While in a hover and making a turn to the northeast, the wind increased, and the helicopter quickly climbed to 75 feet agl. The flight instructor told the student pilot to position the helicopter into the wind and descend. As the student applied left pedal input, the instructor noticed the helicopter started to rotate toward the right. The instructor immediately took the flight controls and continued to apply full left pedal input while “slightly” lowering the collective and using the cyclic to move the helicopter into undisturbed air. The flight instructor reported that he suspected a loss of tail rotor effectiveness and performed a hovering autorotation to land on a field. The helicopter impacted the terrain upright. The helicopter sustained substantial damage to the main rotor blades and fuselage. A postaccident examination of the helicopter revealed no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.