Cold water response poses drowning risk in lakes and rivers

Health authorities are warning about the “cold water response,” an involuntary physiological reaction to sudden immersion in cold water that can lead to drowning even among experienced swimmers. The phenomenon, often referred to as “cold water shock,” can trigger an involuntary gasp, rapid breathing, increased heart rate, and elevated blood pressure, potentially causing a loss of swimming coordination and breath control.

Data from the National Observatory for Drowning Prevention indicates that in the 2024-2025 biennium, 604 deaths were recorded, with 277 occurring in lakes, rivers, and other inland environments. Experts note that inland waters can be deceptive; calm surfaces may hide sudden changes in depth, strong currents, or submerged obstacles. The Istituto Superiore di Sanità emphasizes that entering water slowly can help mitigate the risk of shock.

To manage a potential incident, authorities advise not to panic and to attempt to float with the head above water until breathing is under control before seeking help or moving toward safety.