Who: Sayid and anyone else.
He wasn't sure why he still bothered with the signal fire. The raft, even the radio - those were much more practical, had a much better chance of working. Force of habit, maybe - it did break the monotony of day after day on the beach. Or maybe some part of him felt that he ought not give up on the simple solutions. In the middle of the day, he tried to find pieces of wood that were a little damp. They made more smoke - smoke that no one would see.
He piled a few more logs on the fire and then stood back. The heat of the fire compounded by the heat of the sun was not easy to take for very long.