If you drank sea water, you would have to get rid of the extra salt because it is just too much for your system. Your kidneys would draw water from your body's supply to dilute the salt to get rid of it, a process so dehydrating that you could die of thirst faster by drinking only sea water than if you didn't drink anything at all. There is no convincing evidence that women are more susceptible to hypothermia than men, as commonly stated by divers. To the contrary, several studies show women may be less susceptible. It takes more calories and metabolic work to keep up such heat production, making a very extreme survival situation more problematic for males - they may be more likely to starve and freeze.
Evidence is strong that women protect their core temperature in the cold as well or more than men.
That doesn't mean that men fare better in the cold. It indicates that women are losing less heat through their periphery. Men's warm hands pour heat out into the environment. That familiar number is the average temperature of your core. Skin temperature is far cooler than core temperature.