The Holy Fire is described by Orthodox Christians as a miracle that occurs every year at the Church of the Holy Sepulchre in Jerusalem on Great Saturday, or Holy Saturday, the day preceding Orthodox Easter.
Orthodox tradition holds that the Holy Fire happens annually on the day preceding Orthodox Pascha (Orthodox Easter), in which a blue light emanates within Jesus Christ's tomb (usually rising from the marble slab covering the stone bed believed to be that upon which Jesus' body was placed for burial) now in the Holy Sepulchre, which eventually forms a column containing a form of fire, from which candles are lit, which are then used to light the candles of the clergy and pilgrims in attendance. The fire is also said to spontaneously light other lamps and candles around the church. Pilgrims and clergy claim that the Holy Fire does not burn them.
Here is some footage from this year, you may see people exposing thier beards, faces, hands and arms to this Holy Fire, and it won't burn them. (From 5:13 to 8:22.)https://www.youtube.com/watch?v=Z9Yd7q9wq_Q&feature=youtu.be&t=313