Hi, Last weekend I worked out (weights and 20 minutes on the treadmill) on Saturday, then went for a 5-mile hike on Sunday. This was nothing new for me and a routine I follow quite often. On Monday, my skin hurt to the touch, I had extreme muscle aches, was chilled to the bone and extremely tired. On Tuesday, I developed a 102 fever on top of the above. Today, the symptoms are abating. I had the exact same symptoms and timing the weekend before after the exact same workout schedule. Do you have any idea what this might be?