In Florida, no one seems to pay attention to the risks of hypothermia but it is well worth taking note of in winter months and one should know how to minimize the effects of this condition.
Hypothermia is defined as the lowering of a body's core temperature to less than 95 degrees Fahrenheit. Decreased consciousness occurs when the core temperature falls to approximately 90 to 86 degrees.
Heart failure is the usual cause of death when the core temperature cools to below 86 degrees.
The body loses heat to the water about 30 times faster than in air.
Swimming is an option however swimming increases heat loss (increase by 35-50%) and is not recommended if you are more than one mile away from shore, adopt a heat conserving strategy instead.
The HELP, heat escape lessening position, is recommended. Consider your circumstances carefully before deciding to swim, is there a favorable current to assist you etc..
Treading water also leads to rapid heat loss, avoid if possible, wear a PFD! Do not remove clothing or shoes, they provide insulation (a jacket can trap air and assists floating).