Sudden warm feeling in left arm now.yesterday had muscle pain,chest after huge sneeze,n slightly fast heart rate(if it's related).no other symptoms.

Symptoms only that,: may have many possible bases & are thus inadequate to arrive at reliable diagnosis. Given description, muscle pain mostly likely form sudden abnormally strong contraction producing some damage/pain. Faster heart rate common in response to pain, especially if also scared. All these are only clues, not any necessarily unusual or reliably predictive of any ongoing or necessarily serious body problem.