Answer: ASSESS FOR A CAROTID PULSE FOR UP TO 45 MINUTES.
Explanation: Oweing to the fact that the temperature of the wood is low and the man has been there for up to 18hours leading to his pale, unresponsive and apneic state,the carotid pulse should be assessed to assess his cardiac performance, determine his cardiac rate and rhythm, establish the integrity of his peripheral arterial blood supply or localizing peripheral legions and generally to evaluate the status of the heart,this is because the carotid arteries play a vital role of transporting oxygenated blood from the heart to the brain.