Upon arriving at a campsite explosion where a patient's clothing is burning, what should you do first?

When arriving at a scene where a patient’s clothing is on fire, the first and most critical action is to extinguish the burning clothing. This is paramount because flames pose an immediate threat to the patient’s life by increasing the risk of severe burns, which can lead to shock, infection, and other life-threatening complications.

By putting out the fire, you not only prevent further tissue damage but also stabilize the patient's condition so other interventions can be safely and effectively administered afterward. After ensuring the fire is extinguished, it's appropriate to assess the patient’s injuries, including checking for fractures, and considering other supportive measures like administering oxygen or starting CPR if indicated.

This prioritization is consistent with the principles of the emergency response, which focuses on addressing immediate life threats before moving on to secondary assessments and treatments.