Final answer:
The correct course of action at the scene would be to assess for hazardous environments, secure safety, and request a hazardous materials response before administering aid.
Step-by-step explanation:
Upon arriving at the scene where multiple individuals are experiencing respiratory distress, the appropriate course of action would be to evaluate the scene further for indications of a hazardous environment and request a hazardous materials response. This approach aligns with emergency services protocols that dictate safety and scene assessment as the first steps upon arrival. An environmental hazard could pose a risk to both the victims and the responders, so securing the scene and ensuring safety is critical before proceeding with treatment.
It is essential to dress with appropriate protective gear, like fire-resistant clothing and breathing apparatus, to protect oneself while assessing and responding to the situation. Once the scene is deemed safe or the proper authorities have been notified, one can then proceed to administer first aid and other necessary medical assistance to those affected.