There are some stories of old ladies who state that:

you do not have to wear sunscreen if you have dark skin,

that male products work totally differently from female products;

that wash your face with hot water helps clean up deeply pores.

Obviously they not right: sunscreen is required every day, no matter what your skin colour is; skin benefits from all the same ingredients regardless of sex but water temperature used during facial washing makes the difference.

The truth about water temperatures.

To understand the theory behind washing our face with hot water, we begin by speaking from a scientific point of view: everything naturally tends to expand when exposed to heat; you will think that washing your face with hot water allows your pores to expand, making it easier to clean. Likewise, some versions of this myth suggest that cold water facial cleansing makes pores smaller.
The problem with this belief is that pores are not muscles that can expand and contract drastically. While very hot water can make you feel softer skin immediately afterwards, cold water can make your skin more resistant for a few minutes but the effect will begin to disappear as soon as the skin temperature begins to return to normal.

What is the difference between the water temperature when you wash your face?

While pores can not dilate with temperature changes, other parts of the body may, in particular, blood vessels. Extreme heat can cause dilation of blood vessels, causing inflammation.
Hot water can also eliminate natural skin oils, leaving the skin drier and possibly irritated.
Cold water is less likely to cause skin problems but there are also discomforts.
Cold water is less effective in removing excess sebum that can lead to build upon the skin surface and block the pores over time.

What is the best temperature?

Warm water.

Using warm water, you get the benefits of cleaning with hot water without any risk of burns. Try the temperature inside the wrist where the thin skin is quite similar to that of your face.