Start your morning shower with 30 seconds of cold water. Cold showers boost circulation and release endorphins, making you feel more awake and focused. Studies show that while regular cold exposure can reduce the number of self-reported sick days, a significantly lower number of actual sick days has not been proven. Current evidence (meta-analysis, PLOS One, 2025) suggests that cold water may even temporarily increase inflammatory markers, though the long-term effects are still unclear. Simply turn the water cold slowly at the end of your warm shower and gradually increase from 10 to 30 seconds.