Sounds to me like some typical signs of panic/anxiety. It seems your neck and shoulders tensed up and when it started causing pain your anxiety jumped in. Warm and cold sensations are also a symptom of anxiety.....Some people get really cold and then start sweating because they get so warm after they've been freezing cold. What do you constitute as a tremor? Did your whole body shake and how long did it last, or was it just your hands shaking? I hope by now you are feeling much better!!!!!