My 24 yr son went to bed last night fine but woke up this morning with stomach pain. He has chills but no fever[97.6 temp]. His bp is 110/74 and heart rate of 87. He s vomited twice now[6pm]. He s complaining about leg and back pain. Is it ok to give him tylenol for the aches and chills? He has no appetite for fear of vomiting more. It appears his stomach aches the worst just before he vomits. Do you think I might just a 24 hr bug? He does have a history with heart issues. He had his aorta value replaced and a mitrial value repaired in 2013 due to endocarditis.