The idiom "make one's hair stand on end" is used to describe a situation that is extremely frightening or gives one an intense, chilling sensation. There are several synonyms for this phrase, including "send shivers down one's spine," "give one the creeps," "make one's blood run cold," and "make one's skin crawl." Each of these expressions describes a feeling of fear and uneasiness that is strong enough to cause a physical response. Whether you're describing a scary story, a creepy place, or a hair-raising experience, these alternative phrases can help convey the intensity of your emotions.