freeze your blood
freeze (someone's) blood
To affect in someone an intense feeling of fright, horror, or revulsion. The sight of my brother's murderer in court absolutely froze my blood. When we were camping last weekend, we heard a scream in the night that froze our blood.
freeze your bloodfill you with feelings of fear or horror.
According to the medieval physiological scheme of the four humours in the human body (melancholy, phlegm, blood, and choler), blood was the hot, moist element, so the effect of horror or fear in making the blood cold was to make it unable to fulfil its proper function of supplying the body with vital heat or energy. Compare with make your blood run cold (at blood).