Barbara, I don't know where the rumour about cuticles or pores closing coz of cold water came from. What opens and closes cuticles is a change in pH. The only logic I can see in using cold water and why pple swear their hair looks better is because it probably doesn't rinse all the conditioner off so a bit coating is left which makes strands feel smooth.
I do not use cold water on my head at all. Not only would I get a headache from that but I think I would also catch a cold.
Someone suggested that cold water would close pores. While that isn't true regardless of the number of "experts" that chant that lie, even it had been true, why would you want the pores on your scalp to be closed? I love th( My sebum production is uninterrupted. Keeps my scalp moisturized and with baggying my hair too so that I could go over a year w/o needing a leave-in product for moisture.
OP, if you want to close your cuticles, use lukewarm water with some ACV mixed in.