Final answer:
Passive rewarming by covering the patient with blankets and assessing for frostbite are the immediate steps to take for a hypothermic and unresponsive patient, avoiding vigorous rubbing or rapid rewarming to prevent further harm.
Step-by-step explanation:
Immediate Action for Hypothermic Patient
The next action for a 14-year-old patient who is unresponsive and hypothermic, with their airway already secured, involves a careful approach to rewarming. It is critical not to rewarm too quickly or apply vigorous methods such as rubbing which can cause further damage. Instead, passive rewarming techniques are preferred, where the patient is covered with blankets and allowed to gradually return to a normal temperature. As part of the management, it is important to assess for signs of frostbite and treat any frostbitten areas while avoiding further tissue damage.
While controlled hypothermia is used therapeutically in certain medical situations such as open-heart surgery to reduce metabolic demand and protect organs, involuntary hypothermia like in this case must be managed carefully to avoid complications. In this patient's scenario, active internal rewarming may be necessary if the hypothermia is severe, but such measures should be taken in a controlled environment such as a hospital setting under medical supervision.