At that sort of temperature, hypothermia would have set in fairly quickly and most of those in the water would either have been dead within 30 minutes or in a state of stupor and within minutes from death. Therefore, it throws out of the window all those claims by several male survivors, both passengers and crew, about "swimming for hours" before being picked up; that nonsense was clearly the product of survivor's guilt.
Hypothermia slows down all systems and for a while tries to protect vital organs like heart, brain, kidneys etc. With regard to the brain, that protective effort is largely concentrated with the part of the brain stem that controls vital functions of respiration and circulation and the at the expense of cognitive functions. That would mean that all of the people in the freezing ocean would have quickly become drowsy and slid into stupor even if they were breathing and had their circulation going for a while. So even IF someone like Phillips, presumably a healthy and fit 25 year old man at the time, had made it to the top of
Collapsible B (which I personally doubt), the fact that he died soon afterwards suggests that he would have been in a state of severe hypothermia with total confusion and exhaustion. Phillips most certainly would not have been in a condition to tell Lightoller what the Second Officer claimed that he did in the latter's 1935-36 exchange with Harold Bride. By inference therefore, Lightoller was lying outright.