Hi, Welcome to health care magic, Stomach burning causes could be excess stomach acid or acute gastritis, gastroenteritis,gastric ulcer or Helicobacter pylori infection or food allergy or stress or drug induced. Otherwise it has nothing to do with sun light exposure or there might excess acid secretions inside stomach. You should undergo routine blood investigations and H.pylori,liver function tests,urinalysis and stool for blood and abdominal ultrasound to detect the underlying cause. Treatment is mainly depend on the cause but you may take symptomatic treatment meanwhile. Antacids like h2 blockers (ranitidine) or proton pump inhibitors (pantoprazole or rabeprazole) will help to reduce excess acid production in stomach. You can also take digene gel or liquid or ulcero-protective agents like sucralfate or bismuth subsallicylate to reduce the burning sensation. Apart from medications you should, 1) eat plain foods like boiled rice and green leafy vegetables without adding spices or oil. It will help to neutriluze digestive acids and also they are easily digestible means there will be no need of extra stomach acid. 2) avoid oily,spicy and fast foods 3) avoid eating full stomach at a time rather have small meals frequently. 4) drink coconut water will help to reduce burning. Consult physician or gastro physician for further advice. Regards,