Ive had cold sweats for the last three nights, my body temp is low (Im freezing!), and my back has been aching, lots of joint and musle aches.I am 29, 118lbs healthy ( no allergies)with two systs on my left ovaries (if thats relevant).  I went to Nicaragua in March 2011 and didnt take any shots before going.  I live in Canada.
Hi. It is unlikely that you have some illness 4 years after visiting Nicaragua. But, nevertheless, symptoms you described are not pleasant, and you should check at your doctor. Did you measured your body temperature, or you just felt like cold? Sometimes chills are sign of fever and sweats are sign of body regulation. Anyway, you should use lots of teas and water and I would visit my doctor for these problems. All the best.