I was taught the Wim Hof technique (without knowing its name) several decades ago as part of bootcamp involving swimming in (very) cold water. When it was taugh

I was taught the Wim Hof technique (without knowing its name) several decades ago as part of bootcamp involving swimming in (very) cold water. When it was taught, I distinctly remember the instructor telling us only to use this when preparing for a dive in cold water, never on dry land, precisely for the reasons you mentioned.