My husband has been running a fever and has achy body/joints and exhaustion... His throat gets sore as he fever spikes. He cycles through....feeling crappy (above symptoms) takes Advil.... Starts to have body sweats, then feels better for about 2 hours.... Then starts to feel crappy again...the cycle continues.... He has had a throat swab....negative for strep, blood tests came back....everything is fine..... He's been taking Advil every 4 hours for 2 and a half weeks now. He also has had endocarditis, and has a bicuspid heart valve...he sees a cardiologist yearly. He's 44 years old. any thoughts.? He has seen his family doctor.... She's stumped.... Said if fever gets too high... Go to hospital.