I have a bump on my neck it feels like a knot. should i apply heat and massage?

If it sore or not!: No pain, probably a lipoma or non-infected cyst. You could have focal spasm. Heat and massage may help and won't hurt. If it doesn't go away see your doc.

Need more info: How large is it? Where on the neck? How long has been there? Is it mobile? Is there a color to it? Some possibilities are an inflamed lymph node, an abscess, thyroid nodule, cyst, tumor, skin cancer, muscle spasm, etc. You should have a physician evaluate any mass that does not resolve on its own in a reasonable amount of time.

Need more: Heat and massage may help, depends on what it is. I would recommend being seen by your physician for full exam and history taking. Depending on size and depth and course, it could be anything from a bug bite, to lymph node, to muscle spasm. Need more info - onset, location on neck, duration, character, aggravating factors, relieving factors, constant or temporal, fever, sweats? Other symptoms?