Final answer:
The best intervention for this patient is rapid sequence intubation and endotracheal intubation. This will secure the patient's airway and provide oxygenation in the case of severe airway compromise from inhalation injury.
Step-by-step explanation:
The best intervention for this patient is Rapid sequence intubation and endotracheal intubation. Given the patient's symptoms of a harsh, stridorous cough with sooty sputum, singed hair, and elevated vital signs, it suggests severe airway compromise from inhalation injury. Intubation will secure the patient's airway and provide oxygenation.