Fear of cold and heat in incisors can be seen in dentin sensitivity, reproducible pulpitis and irreversible pulpitis. Depending on the situation, desensitization, medication or root canal treatment is needed. 1. Dentin sensitivity: fear of cold and fear of heat in incisors may be due to exposure of dentin tubules caused by tooth abrasion, wedge-shaped defects, etc., and the teeth are sensitive to external stimuli such as hot and cold, sweet and sour, and mechanical stimuli. According to the severity of sensitivity, strontium chloride drug desensitization treatment can be taken, the use of resin filling wedge-shaped defects, serious need to do crown repair. 2. Reproducible pulpitis: when tooth decay is too deep close to the pulp, it can cause reproducible pulpitis, the surface of the tooth will produce transient pain to external hot and cold stimuli. The treatment generally uses clove oil medication to pacify the pulp, asymptomatic after the cushion resin filling. 3. Irreducible pulpitis: tooth decay or external stimuli, can cause the pulp can not be restored to the outside world of hot and cold stimuli produce severe pain and pain can be sustained, the general root canal treatment after the crown restoration. Incisors are afraid of cold and heat, it is recommended to go to the hospital in time to check and deal with, to avoid aggravation of the symptoms.