Take 5–10-minute cold showers before breakfast and/or before bed. Use hot water for 1–2 minutes over the entire body, then step out of water range and apply shampoo and soap to your hair and face. Turn the water to pure cold and rinse your head and face alone. Then turn around and back into the water, focusing the water on your lower neck and upper back. Maintain this position for 1–3 minutes as you acclimate and apply soap to all the necessary regions. Then turn around and rinse normally. Expect this to wake you up like a foghorn.
