65 yr old husband nfw w/ low grade fever and a pain on his left side he says feels like in his rib cage. He has low blood pressure, low cholesterol, not over weight at all and in good health. We have had flue in the house and this hit him pretty suddenly...he said he ached over more of his body earlier today and now seems to be in the left rib cage area..should I take him to a doctor this evening? Thank you.