Cortisol is the “fight-or-flight” hormone that the body releases in response to stress. Lowering cortisol levels in the blood may therefore help reduce stress levels. Researchers note that when people immerse themselves in a bath of cold water, their cortisol levels drop.

Another way cold showers may work is by increasing endorphins, or the feel-good hormones in your brain. Endorphins can ease symptoms of depression and anxiety. Cold water may also decrease cortisol, a stress-inducing hormone.

The report suggests that cold showers also can increase endorphins that ease symptoms of depression and anxiety and decrease cortisol, a stress-inducing hormone.

Two-hour-exposure to cold air (5 - 15o C) increased the serum cortisol levels (12,13), and if physical stress and cold water showers were added, the levels in- creased even more (14). Some studies have reported de- creased or (3,15) unchanged in serum cortisol levels (16- 18) in response to cold.

Medical research has supported the use of hot and cold baths, as well. Decreases in stress hormones (like cortisol) have been reported with water bathing (Toda et al., 2006).