Heat helps tightened muscles relax,  and moist heat is better than dry heat, as it can penetrate into the neck more effectively. Apply heat to the back or neck area for at least 20 minutes at a time, 3 times daily. Place a hand towel in a bowl full of hot water, or pour the hot water all over the towel. Alternatively, put the towel in the dryer for 5-7 minutes. Dry out the towel just enough so that it is not dripping, but still has its warmth. Drape the towel over your neck when your neck is stiff or sore. After that is done  wait about 20 minutes a do it again. Keep doing this about 3 times. Cold dulls local pain and limits the buildup of lactic acid, which can cause soreness. Use an ice pack and place it on the part of your neck that feels stiff (usually the back of your neck at your hairline). Hold the pack there for 10-15 minutes every 2 hours.   You can also try a more comfortable position to ice your neck. Sit in a comfortable chair and rest your head back. Place the pack between your shoulders and the bottom of your head. Lean back against it so your neck gets the full benefit of the cool temperature. Some experts feel that ice will contribute to increased stiffness in the neck because the cold will contract your muscles. Try what feels good to your neck. Use a cold treatment for acute pain in the first 48-72 hours, and then switch to heat.

TL;DR in Chinese:
在脖子部位进行湿热敷。 将热毛巾敷在脖子上。 用冰袋舒缓脖子。