13 species of Fire corals are found on reefs in the Indian, Pacific, and Atlantic Oceans and the Caribbean Sea. They form extensive outcrops on projecting parts of the reef where the tidal currents are strong. They are also abundant on upper reef slopes and in lagoons down to 40 m deep. 

Upon contact, an intense pain can be felt that can last from two days to two weeks. The very small nematocysts on fire corals contain tentacles that protrude similar to jellyfish. If you are stung by fire coral avoid rubbing the area as it is more likely to push more venom into the skin.   

Rinse with seawater. ...

Apply topical acetic acid (vinegar) or isopropyl alcohol.

Remove tentacles with tweezers.

Immobilise the extremity because movement may cause the venom to spread.

Apply hydrocortisone as needed for itching.