What occurs during a submersion event?

During a submersion event, one of the critical physiological responses is that the supply of oxygen is significantly reduced or cut off to vital organs, especially the brain and heart. When a person is submerged underwater, they are unable to breathe, which means that oxygen cannot enter the body. Without adequate oxygen, vital organs begin to function poorly and can suffer damage or begin to fail. This is especially problematic for the brain, which can start to experience irreversible damage within just a few minutes of oxygen deprivation.

The other choices present scenarios that do not accurately reflect what happens during a submersion event. Breathing does not resume under water, as the person cannot take in air. The body does not warm up; rather, hypothermia can begin to set in quickly, especially in cold water. Additionally, swallowing water does not increase oxygen availability; it exacerbates the situation by introducing liquid into the lungs, which can lead to drowning and further restrict oxygen access. Thus, understanding that the disruption of oxygen supply to vital organs is the primary concern during a submersion event is crucial for lifeguards and first responders.