Low to mid 70's water temperature was cold? Maybe you should change your screen name to mrsmcmasty.
Did you jump in and do some warm-up strokes before the race started? That usually takes care of the initial shock. The temp was around 62 in my race yesterday and it was fine a few seconds after my original plunge.
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Fredo, you're my older brother and I love you...but don't ever take sides, with anyone, against the family again...ever.