The sprinklers are activated by high temperature, which melts a link and causes the sprinkler to discharge water in a limited area. If the fire is not controlled, other sprinklers will be activated as the links melt. Automatic fire pumps maintain water pressure within the system. An activated sprinkler head will trip a water flow detector, which will activate the fire alarm system. Dry risers on each floor also provide a connection for firefighters to hook their hoses to extinguish the fire.