Titanic sub crew discovers how to extend oxygen supply beyond 96 hours

Five passengers aboard a missing submersible could potentially conserve oxygen and make their limited supplies of breathable air last longer, according to medical experts. The survival challenge for the passengers will be to remain calm and lower their heart rate so as not to use too much oxygen or produce too much carbon dioxide. Breathing techniques such as deep and controlled breaths encourage slower oxygen consumption, thus reducing stress levels. Medical experts have also warned that even if the crew survives the experience, the lack of oxygen could cause severe symptoms. While sleeping pills could reduce oxygen consumption, too much exposure to CO2 can be deadly and lead to hypercapnia. Another challenge for those on board would be the hypothermic environment where the sub may be stranded, as the sea temperature is only a few degrees above freezing.