It helps by stimulating the production of interferon, a natural virus killer. It's O.K. to take upwards to 1000 mg every hour with flu symptoms. Drink Lots of Liquids. Freshly squeezed fruit juice is best, but frozen will do in a pinch. Sometimes a short stroll around the block can have an energizing effect on your immune system.
Deep breathing is another natural energy booster.
Let the fresh air invigorate you. Please, don't exhaust yourself by overdoing. Take a Hot Bath. A steamy tub would be very comforting at this point. Add pungent herbs for some aromatherapy and sea salt to draw out toxins.