Yes. My 65 y/o husband, who never complains, had fever all day at work. No other symptoms, except he stated his lower back hurts. He took 3 advil at 6:30pm. I just took his temp - 100.1. Unfortunately, I do not know what it was earlier, however, he was sweating ALOT when he got home at 7:30pm; I assume from advil breaking fever. Therefore, I am at a loss to figure out what is causing fever.