According to the Mayo Clinic, red hands are a common symptom of Raynaud's disease, a condition in which the blood vessels overreact to temperature changes and stress. The blood vessels of the fingers and toes experience intermittent spasms, causing the hands and feet to change color from grey to red.
WebMD explains that Raynaud's disease, also referred to as Raynaud's phenomena, has no known cause but is often a symptom of underlying conditions such as lupus or sclereoderma. The most common trigger of a Raynaud's attack is exposure to cold temperatures. During an attack, the blood flow is limited to the hands and feet, which turn blue in color. Once the spasms reside, the blood resumes its normal flow, causing a temporary burning sensation and bright red color in the hands and feet.