Raynaud’s is a condition that may cause some areas of your body to feel numb and cool in response to cold temperatures or stress. Raynaud’s causes occasional narrowing of blood vessels, limiting blood flow for brief periods of time. This is called a vasospasm, and it occurs when the skin is deprived of oxygen and may become pale and then turn bluish. As the blood vessels relax and blood flow resumes, the skin may become red.