How long does it take for ice contact to cause frostbite?

Depends on size/area: Frostbite occurs when the cold injury causes the tissue to die from cold exposure or the vascular supply to thrombose. Typically extremities are more vulnerable such as the tips of fingers or nose. Larger areas with better blood supply may be able to tolerate cold exposure for longer periods due to their ability to be closer in proximity to the core and maintain circulation.