I can't remember a time when I didn't have night sweats. The severity and frequency shift around which seems to correlate with all the reasons suggested by Melissa75. Sweats effecting the extremities has about 20 potentil causes. Night sweats of the extremities can be reduced to about four issues and CF narrows down the probabilities.
The sympathetic nervous system, the vagus nerve and its many branches controls sweating. Nodules in the lungs along the bronchials and such can cause peripheral sweat attacks which could be hands/feet to entire limbs. The nodules could be reacting to infection, scarring or any number of stimuli treading upstream through the vagus nerve. Everything diabetes can cause localized sweats due to neuropathy, diabetic-metabolic issues and secondary endocrine problems.
My night sweats have become morning, noon and night sweats pointing at either an occult infection or an autoimmune hooha possibly. The subtle increase in dispersed infections, possibly several tiny colonies throughout the body can sneak up on a person. This is part projection because a couple days ago I woke up needing to rush to the ER. Half expecting to find an intestinal obstruction my wife and I went slack jawed when the doctor confirmed acute pneumonia. I may have been walking around with this a year or caught a wiff of somebody's infected exhale last week. The point is, I didn't know about this and neither did half a dozen doctors I had seen recently.
Something rather obvious that may have been overlooked, has anybody put winter bedding out? We can't make it through a night w/o pushing the covers back or a foot out. More practical right now is an old trick and that is a foot tent. That is, a tent structure that keeps the covers off the lower legs, usually made from a frame of sturdy wire, wood or plastic. Other uses include isolation of the feet/lower legs for diabetics w/sores, general bed sores for back sleepers etc. Once you have open air around the lower legs you can vent it more or less just by controlling any one or two openings created by folding back a little bedding.
If this is not going away soon enough, a doctor will be needed, the trick may be in who best to help. Infectious Disease Specialists (IDS) or virologists are infection detectives best paid by the job. The investigation could go over and over the same steps until a catch is made. If you are fighting a single big infection or many small ones that are the same bug a diurnal fever, one that exagerates your circadian rhythm could be at work. If night sweats are not with elevated temperature, an infection may not be the direct cause. So if your night sweat is at 3am and your normal temperature for that hour is up a degree or more, that's a fever. You also should have a higher than normal mid day temperature, maybe 100 to your normal 99 mid day high.
The dramatic sweats some people are describing may be resolved with some clever tenting and ducting. The classic muffin fan used for cooling electronics is quiet and easily rigged to provide quiet, focused air flow. In Korea, they have some interesting tools for keeping cool during their oppressive hot humid summers. A basket woven tube resembling a five foot hot dog with an open airy shape, placed next to a person providing excellent air flow. Koreans are beginning to use western pillows but many prefer a ceramic pillow, resting in a hard smooth cradle. The common pillow for others is a buckwheat pillow, some going to a ceramic bead pillow for maximum air flow and kilocalories of heat sink. In the back of my mind a memory of something that can be rubbed on the offending skin to prevent sweat outs. Anybody?
Wish I had something more useful,
LL
P.S. pillow freezer packs can last all night. Possibly the same thing can work at the feet. Aluminum chloride, an antiperspirant chemical is available for general skin application and some that are better.