Cold stunning occurs when sea turtles are exposed to rapidly dropping water temperatures, causing hypothermia-like incapacitation. Mass cold stunning events strand thousands of turtles annually, particularly in Cape Cod Bay, Massachusetts — and the wildlife rescue response is one of the largest annual sea turtle welfare operations in the world.
Cold stunned turtles are in a genuine medical emergency: hypothermia impairs cardiovascular and neurological function, and prolonged incapacitation in cold water leads to secondary pneumonia, circulatory failure, and death. The welfare harm is both acute (the experience of hypothermic incapacitation) and potentially prolonged (the days or weeks of rehabilitation). The extraordinary success of the Cape Cod cold stunning response demonstrates that large-scale wildlife welfare intervention is logistically possible and welfare-positive when well-organised: thousands of volunteers, coordinated transport, and professional rehabilitation facilities work in concert to rescue animals that would otherwise die. This is one of the best-documented examples of organised wildlife welfare response achieving genuinely good outcomes at scale.