My 15 year old son was sick for several days with a fever, chills, and sore throat. He had a negative strep test. Although he is feeling much better now, and is eating and drinking normally again, he has been feeling dizzy and lightheaded and is concerned that his resting heart rate, which is usually near 80, is only about 60, even after running up and down the stairs. He tends to worry a lot, so I'd like to reassure him without brushing his concerns aside. Should I call our doctor?