Tongues of fire

When the day of Pentecost arrived, they were all together in one place. And suddenly there came from heaven a sound like a mighty rushing wind, and it filled the entire house where they were sitting. And divided tongues as of fire appeared to them and rested on each one of them. And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit gave them utterance.
Acts 2:1-4

This was the first time anyone was baptized with the Holy Spirit and two things happened to them: tongues of fire appeared and rested on each of them and they spoke in other tongues.  There would be other occasions when people were baptized by the Spirit and spoke in tongues but this is the only time tongues of fire appeared.