Chilblains (perniosis, also known as pernio) is a reaction to cold, nonfreezing temperatures. It is seen most often in young people who have Raynaud's phenomenon and people who are exposed to damp, cold weather.
Symptoms develop 2 to 14 hours after exposure to cold and usually affect the hands, ears, lower legs, or feet. Symptoms include:
Appears to have a seizure with uncontrolled, rapid shaking
Has trouble breathing
Hits his head before or during a convulsion
Is unconscious for several minutes
Might have ingested something poisonous