Hi, my sister is 60 yrs old occasional stress induced hypertension, physically fit outdoor hiking on weekends,but the last couple days she is having shivering (am and pm lasting over 20 s).Seen PCP and instructed to take tylenol and diuretics to lower HTN (160 s) . The fever 102 came down , but she still feels chills and shivering...she is urinating ok, no other complaints