Sorry, is this an insomnia discussion or like a "I'm hot before bed" independant of how the sleep goes kinda deal?

I would advise against cold showers/baths/immersion as the will shock you into wakefullness and vigilance. Can't see how there's any evidence for that actually working. Its like saying "Ya, I turned my phone as bright and blue as it goes up to and I STILL couldn't sleep" :/