Rabbi Mendel Bluming has often been asked by congregants in Potomac, about the 9 days practices, a period of time during which we mourn the destruction of the Holy Temple.

As tradition dictates, freshly laundered clothing is not worn during this period (other than Shabbat), however that is only if they are put on for comfort or pleasure. Those who are accustomed to changing their shirts regularly because of dirt or sweat in the heat of summer, may do so even during the 9 days, even if the shirt is freshly cleaned from beforehand.

Menachem Mendel Bluming quoted from Rabbi Goldstein at ShulchanAruchHarav.com who sources this in Kinyan Torah 1:109; Piskeiy Teshuvos 551:17