Eating cold or hot teeth will hurt: First, it may be due to tooth sensitivity, tooth enamel is damaged, dentin is exposed, so when encountering cold, hot, sour, sweet and other stimuli, toothache will occur. Second, due to tooth decay or pulpitis, because when the tooth decay in the middle to deep caries, the bacteria will erode to the body of the tooth, may slowly reveal the tooth nerve, the tooth nerve will produce pain when encountering cold or hot stimulation. If the tooth decay is not treated in time, the tooth will develop into the late pulpitis, once the pulpitis occurs, the tooth will have the irritating pain turn into the autonomous pain, the frequency of pain will be higher, especially when eating cold or hot the pain will be more serious, so you should go to the hospital for timely examination.