"Warm the blood" is a phrase that refers to something that excites or stirs up emotions or passions. There are several synonyms for this expression that can add variety and depth to your writing. One synonym is "ignite the soul," which implies a deep emotional connection that goes beyond mere physical warmth. "Enliven the spirit" is another synonym that can evoke a sense of renewed energy and enthusiasm. Another option is "foster ardor," which suggests a passionate commitment or devotion to a cause or pursuit. Ultimately, the choice of synonym will depend on the context and tone of your writing, but each option can add nuance and color to your prose.