If you keep getting those sweats for several days in a row, be sure to see your doctor. Cytomegalovirus (CMV) is something that remains dormant in most people, some do have reactions to it though. I had a reaction several years ago that ended up causing me to have not only night sweats, but sweats throughout the whole day. You should take your temperature periodically to see if you're running high. I was running fevers constantly, which ended up causing more damage to my lungs. My doctor admitted me for 3 weeks and had me do many tests until they finally came to the conclusion that it was CMV. When we (Cfer's) catch bugs from our companions, we need to be extra cautious since things have a tendancy to attack us more than those without CF.
I'm really grateful for the mild, relatively sick-free winter we're having here in RI!!!!