Opening the guide…
Alternating hot and cool water to feel refreshed.
Begin with a comfortably warm shower for a minute or two to relax.
Switch to cool for 20–30 seconds, then back to warm for a minute. Repeat the cycle a few times.
End on the cool phase for an invigorated feeling. Keep the cold mild if you're new to it.
This should feel bracing, not painful. Ease off the contrast if it's ever too much.
These are general preparation techniques — not treatment for any condition. Always consult a doctor before acting on anything you read here.