Elevated body temperature may be caused by the following: 1. Infectious diseases: such as viral infections, bacterial infections, mycoplasma infections, rickettsial infections and other infections caused by various reasons. 2. Physiological elevations: such as emotional stress, after strenuous exercise and excessively hot weather, female pregnancy, etc., can cause physiological elevations, but such elevations are often relatively low. 3. Blood system diseases: such as Aplastic anemia, leukemia, lymphoma, etc.; 4. Connective tissue diseases: such as systemic lupus erythematosus, arteritis, hyperthyroidism, etc. 5. Tumors: such as liver cancer, lung cancer, etc. If the body temperature is elevated for a long time, you need to go to the hospital for a clear diagnosis and early treatment is possible.