how to get blood out of sheets, start by rinsing the affected area with cold water as soon as possible to prevent the stain from setting. Next, apply a small amount of hydrogen peroxide or a mixture of water and baking soda directly to the stain and gently rub it in. Let it sit for a few minutes before washing the sheets in cold water with laundry detergent. Repeat the process if necessary until the stain disappears.