It is possible that the symptoms you reported (chest pain in the mid section and to the left side) might be related to heart issues. An ECG might reveal the exact nature of the problem if performed at the same time as when the pain is present. Otherwise, the ECG might miss the changes in the heart muscle's conductivity if the pain is already gone and did not leave any damage on the heart muscle.


It also seems likely that the pain you described might be of muscle origin. Certain of the thoracic muscles might be inflamed due to exposure to cold or extreme exhaustion. In both instances, the best way to treat the muscles would be to reduce the inflammation and keep the muscles calm as much as possible.


It is also possible that chest pain in the mid section of the thorax might be related to esophagus issues. Pain in that area might be present if the esophagus is inflamed or its mucosa is hurt by the reflux of the gastric acid. However, this pain rarely spreads to the left side.


You might want to visit a cardiologist to check for your heart condition. A physical examination, positive anamnesis about acid reflux, and an x-ray that might reveal causes for esophageal reflux might explain the middle chest pain.


If both conditions are ruled out, then you might want to consult with your family doctor if the pain is related to the thoracic muscles and if taking anti-inflammatory drugs under a doctor’s supervision would be helpful.