Make sure that you are completely stretched and have plenty of water handy. You definitely don't want to pull any muscles or become dehydrated. If you begin to feel very tired during a workout, just walk back and forth in the room, but NEVER completely stop moving until your heart rate is back to normal. Try doing warmups for a little while longer than normal. Don't come back from your break and do workouts at the same intensity, take it easy on yourself, and slowly build back up to where you were. Basically just remember that it takes a little while to get your body back to where it previously was and back into routine, and it's best in the long run to go slow and stay safe