Final answer:
The first action when arriving at a 'man down' scene should be to assess the patient's level of consciousness to determine the extent of the emergency and appropriate next steps, potentially including administering oxygen or starting CPR.
Step-by-step explanation:
When you have arrived at the scene of a call for a 'man down' and observe a male in his mid-60s who is awake, exhibiting profuse sweating, cyanosis of ears and lips, and rapid, shallow respirations, your first action should be to assess the patient's level of consciousness. This provides immediate insight into the severity of the patient's condition and should always precede interventions like administering oxygen or checking blood pressure. If the patient is unresponsive, you would then proceed to the next steps in emergency care, potentially including administering oxygen, checking vital signs, and performing CPR if necessary and appropriate.