Ive started having a hot spot that comes and goes on right calf (feels like warming up on the inside). no swelling and the skin isn't hot to the touch (its actually pretty cool). the warmth is becoming more frequent. what could this be?

If you've been exercising or walking a lot it could be a muscular overuse symptom. Another possibility is an irritable superficial nerve. A localized pooling of blood in a vein tributary can also cause a sensation of warmth. In any event I would consider this a nonserious symptom but you could have your physician examine& advise you for peace of mind.