Waking up in the middle of the night. sweating back of neck and head. back of neck is stiff?

This could be related to the position of your neck during sleep. If you are sleeping on your back, try sleeping on your side to see if this relieves your symptoms. If it doesn’t, see your doctor to get your neck examined and see if you need further testing to make the proper diagnosis. Further treatment would depend on the diagnosis. Best of luck to you!

Agree with Dr. Ferranti about the stiffness. To address the sweating you may need to reduce the temperature and amount of covers. Using a fan may be helpful. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get Covid vaccine. Wish you good health!

I agree with Dr. F's recommendations. Night sweats about the head and neck , if mild, they may be benign, but heavy sweating can be caused by serious medical disorders like inflammation/infection somewhere in the body or certain malignancies like lymphoma. Be sure to see a physician if significant night sweats continue and can't be explained by hot environment, too heavy sleepwear,blankets,