The key to cleaning blood from carpet is simple: always use cold water, never hot. Blood is a protein, and heat cooks it into the fibres and sets the stain for good. Blot a fresh spot with cold water and a mild solution and most blood lifts cleanly. Dried blood needs softening first, then a stronger method. Here's exactly how to handle both, without setting the stain. The one rule for blood stains: always use cold water Always clean blood with cold water, never warm or hot. B