Bacterial infections: Like UTIs, bacterial vaginosis, or jock itch. Yeast overgrowth: Especially in women, due to moisture and warmth. Skin irritation: Friction + sweat = chafing and rashes. Odor: Bacteria breaking down sweat can cause unpleasant smells. Body acne: Dirty fabric can clog pores and cause breakouts. When Might It Be Okay? Low-risk situations include: You didn’t sweat much. The...