What is the appropriate action to take when treating a patient with frostbite?

When treating a patient with frostbite, the most appropriate action is to protect the injured areas and maintain the patient's core temperature. This approach is crucial because it helps prevent further tissue damage while also addressing the body's overall condition, which can be compromised due to hypothermia or shock. Protecting the frostbitten areas ensures that they are not exposed to additional cold or trauma, which could exacerbate the injury.

Maintaining the core temperature is important because the body needs to function optimally to manage the effects of frostbite. When a patient is experiencing frostbite, they may be vulnerable to hypothermia, so efforts should be made to warm them gradually and safely. This can involve using blankets or heated packs on the torso, not directly on the frostbitten areas.

The other options, such as soaking the affected area in hot water, attempting to thaw the fingers immediately, or applying ice packs, can all lead to further complications. Hot water can cause burns to frozen tissues, immediate thawing can result in severe pain and additional tissue injury, and placing ice packs directly on frostbitten areas could worsen the frostbite. Thus, option C is clearly the best choice for ensuring the patient's safety and well-being in this situation.