Direct contact with cryogenic liquids can cause which injury?

• A. Frostbite
• B. Heat stroke
• C. Chemical burn
• D. Radiation burn

Answer: (A)

Extremely cold cryogenic liquids freeze tissue on contact, because they suck heat away from the skin far more quickly than the body can supply it. Liquid nitrogen, for instance, is around -196 C. That abrupt cold causes rapid freezing of skin and deeper tissues, forming ice crystals inside cells and constricting blood vessels. The result is tissue damage that manifests as frostbite, a cold burn that can be serious if exposure lasts even briefly. The other options don’t fit because heat stroke comes from overheating the body, chemical burns require caustic substances, and radiation burns come from exposure to harmful radiation, not from touching a very cold liquid. Protecting skin with appropriate PPE and treating frostbite with gradual warming if exposure occurs are key steps.