Hi benkam and welcome to the Board!
The urologist who was managing my care shortly after I was diagnosed about twelve years ago suggested soy supplementation for the hot flashes. That seemed to help. Also, there is one respected study that indicated soy can help a little in combatting the cancer.
I have used fans of various types, aiming the air flow at the neck during the day, with a room fan at night. I found that zippered sweatshirts were a convenient way to adjust to flashes.
For me, the flashes and sweats were never severe enough to warrant medication, but there are medication options that are highly effective for most of us.