From the Great White North.....
there's something called "tempering" and its a lesson I've taught all my kids. We get tempered to our climates. I can swim in freezing cold water and I can stand minus temps without a jacket.... How? You temper yourself to the climate. You have to learn how to re-climatize your body to the temps..... it's easy to do and also a mind set.
Your body gets used to a certain condition and then it adjusts to it, if you change the condition then you get cold or hot; you'll see the Californians wearing jackets in their winters when the temps are like Tshirt weather for us.
You may not notice this as much in warmer climates, but I used to work in Edmonton, outdoors and the first time it hit -20C we'd just about crap (November), then it would get to -30, -40, and sometimes colder well into January. By the time the temps hit back to -20 we'd all be running around without our jackets saying how warm it was. This is a true story.
It also becomes a mental thing. If you tell yourself that the water is too cold to swim in at 65F, then it is and you'll have to wait until July when it goes over 70F; but if you tell yourself that 65 is acceptable, then you'll be water skiing like a pro in no time because you just extended your water skiing season by 3X's
Hope it warms up for you..... I always tell my wife she should've been a California girl, she doesnt care for the cold either.