I continue to have the following symptoms, which started over 24hrs ago. Constant alternating of Extreme chills (eased by Tylenol),then extremely sweaty all over Headache Severe low back pain causing insomnia Moderate abdominal pain. Unquenchable thirst. I've been drinking about 24 oz of water every hour or two,including through the night. I don't understand why i have such serious low back pain that I can't sleep for more than hour at a time. And the abdominal pain. With extreme chills???