The primary danger upon immersion in cold water is __________.

The primary danger upon immersion in cold water is often identified as involuntary gasping leading to water inhalation. This response occurs when a person suddenly enters cold water, triggering an automatic response of gasping due to the shock of the cold temperature. When this gasp reflex occurs, it can unfortunately lead to inhaling water, which can quickly result in drowning.

Recognizing the immediate risks associated with cold water immersion is critical for safety. Involuntary gasping can happen almost instantly, especially when a person is not prepared for the cold. This can prevent them from being able to respond effectively to the situation, such as swimming to safety or calling for help.

Other dangers, such as hypothermia from prolonged exposure, can indeed be serious, but they typically arise after some time in the water. The initial threat during immediate immersion is the shock response that can lead to inhalation and drowning.