One of the things they teach during crisis management is that to keep people calm, give them something to do. It doesn't have to be important, but giving them a task can help them keep cool, since panic is contagious. IF, and this is a massive if, this actually happened, this is why. They didn't need ice, but they could have him go somewhere else and feel like he's helping. And when he comes back with all this ice, the firefighters have a lot of cold water to drink...