Do sweat pores change diameter?
Pores don't change size; that is, the diameter of pore does not increase or decrease in hot or cold environments. Your skin, where pores are located, is not muscle but an organ so the pores don't contract or expand.



Pores can become clogged with dirt, oil, and debris (make up). When pores are clogged, you are more inclined to notice which would cause the illusion that the pore is bigger.


  It's important to know that you can't actually "shrink" your pores. They're nothing but small openings in the skin -- because they don't have muscles, they can't open or close. So although you can't physically change the structure of your pores by making them smaller, there are things that you can do to minimize their appearance$^1$.