Jumping into cold water at the peak of heat - much more dangerous than you thought

On hot summer days, when the heavy heat exhausts the body, there is nothing more tempting than jumping into cool water for an immediate refreshment. Whether it is a lake, a stream, or a spring, the thought of quick relief from the blazing sun draws many to seek refuge. However, behind the action that seems natural and enjoyable hides a real and unexpected life-threatening danger.

Professor Eitan Friedman, director of the Institute for Early Detection Genetics at Assuta Ramat HaHayal, warns that a sharp transition from extreme heat to cold water may trigger an acute physiological reaction in the body known as "cold shock." According to him, this is not just a fleeting feeling of discomfort, but a dangerous chain reaction that could cause involuntary breath-holding, sudden inhalation of water, and ultimately lead to drowning.

The "cold shock" phenomenon is an uncontrollable physiological reaction of the body. The sudden encounter causes blood vessel constriction, an increase in blood pressure, and above all – a reflexive cessation of breathing. To illustrate the intensity of the physical experience, Professor Friedman describes:

"I liken it to someone taking pliers and squeezing your chest. You hold your breath."

The lethal danger lies precisely in this moment; the pressure and the instinctive need to inhale air become a trap. "If your head is in the water at the first moment, you can inhale water and that causes drowning," he clarifies, emphasizing how an innocent act of refreshing oneself can end in disaster within seconds.

The described physiological danger does not remain a theoretical warning, but is backed by real data from the field. The statistics are based on data from France, where an increase in the number of drowning deaths was recorded, with the data indicating that the phenomenon is particularly prominent in cases that occurred in lakes.

"As a concept, jumping from great heat into cold water is not a good thing for any age group, certainly not for older people," Friedman clarifies. Instead of an impulsive jump, he recommends a measured and responsible approach: one should enter the water slowly and gradually. This simple action allows the body to adapt to the extreme temperature change and prevents the sudden "cold shock" reaction, which includes involuntary breath-holding and the risk of drowning.