After I do Zumba, I wait 'til I quit sweating (I sweat more than anyone in class, always have sweated profusely when exercising or in the summer heat), theni I shower and dress. Later, anywhere from a half hour to two hours, I get chilled. My hands and feet get numb. What can I do to prevent this?
I agree with @Janis about consulting your doctor. Numbness and tingling after exercise is something your doctor should diagnose.
According to reports in Medical News Today, many people exercise without replenishing the body of necessary electrolytes that carry potassium and sodium and that serve to regulate the nerves and muscles. The loss of potassium and sodium that results from sweating during exercise can cause numbness and tingling in the extremities.
Given that you sweat profusely, that is a likely cause of your numbness. Good sources of potassium are bananas and vegetables. The World's Healthiest Foods has a complete list. Sodium is salt. So your answer may be as simple as replenishing your electrolytes with food or drink.
As to why you sweat excessively, there are lots of causes of profuse sweating. Some causes are perfectly normal and may be genetic. Here is a long list of some possible causes that are associated with medical conditions.
As others have suggested this may be linked to potassium levels and you would do well to discuss this with a doctor.
The symptoms you described immediately reminded me of hypokalemia, or low potassium levels:
1) "Tingling sensations in the hands and feet may also be a sign of hypokalemia and signify a weakening of the nervous system."
2) "...excessive sweating from playing sports or exercise can lead to a drop in potassium levels and feelings of fatigue."