Was the water really cold? It had seemed to be and everything suggested that it should be freezing but Mark could not feel anything even when he was submerged in it.
But when he tried to move his hands, they proved to be an obstacle. Not only did his body feel heavy and sluggish, but his clothes were another obstruction he was faced with. The water was already limiting his mobility and all the factors she combined together made for a miserable time.
It was only after he tried to move his leg to propel himself up did he notice that this stiffness was different from the one he had faced till now. It felt external rather than being an internal restriction.