This is what is written in my book i have.
There are 2 ways to take a shower, this is used mostly by patients in european clincs. First there is an alternating hot/cold shower.
Then they say to dry brush after this, but you can dry brush before if you like.
First take a 3 min. shower to feel warmed up, then take a cold shower for about 10-20 secs. Repeat this 3x always finishing with cold,as cold as you can stand.
after this shower and rub yourself with a coarse towel, then give yourself another dry brush to warm up.
This one is for people who aren't that healthy.

The other way is supposed to be suitable for healthier persons.
Dry brush first then finish with alternating hot/cold showers. If you cannot tolerate hot showers use warm water.

The alternating hot/ cold shower has an exceedingly beneficial and stimulating effect on all vital functions of your body, particularly on the glandular system and rejuvenates the skin..

This book was written in Europe, the way to do the showers maybe different here.

I say whatever feels comfortable to you.
I usually do a few mins. of as hot as i can stand, then a
min or so of as cold as i can stand.

Hope this helps.