Some of the wilderness areas where fires are fought, do not have easy access. The helicopter is uniquely suited for this task. They can quickly insert crews based on the fire fighting strategy. They can also extract crews quickly if things aren't going so well. Risk must be minimized through careful planning and training.
Communications are a key factor in safety.
With all the air traffic in and around a fire, everyone needs to monitor the correct frequency. If the aircraft is not equipped to transmit and receive on the appropriate frequencies, then you should not be near the fire. The chances for a midair dramatically increase without proper communication. Another hazard near and dear to the helicopter pilot is wires. The altitudes that the helicopter pilot operates at, leaves him particularly vulnerable to this hazard.