My mother is 84 years old and over the past month has had three similar episodes that have come out of the blue. She begins to feel cold, teeth chattering and hands shaking. She feels week and lays down. Next thing she is sweating and her temp is up to 103. She also complains of a dull, achy pain in her lower right abdomen area. The first time this happened my sister took her to the ER and they ran about 6 or 7 different tests. Everything came back negative. Her latest episode was yesterday afternoon on her way home from the bank.