Summarize:

While your skin is likely itchy, scratching only further irritates it, and can increase the duration of the reaction and even cause it to spread further. Do not itch or touch the affected area. Note that if scratching is particularly tempting, try wearing gloves or mittens while at home. If this is uncomfortable for you, clipping your nails can also help. Anything to delay the instant gratification of scratching deters you from indulging in the behavior. Tight clothes can rub against a skin rash, further irritating the area. Wear loose-fitting clothing or, if possible, clothing that does not cover the affected area at all, such as shorts or t-shirts.  Moisture and heat of any kind can sometimes irritate a skin rash, so make sure the clothing is lightweight and made from a material that dries quickly, such as cotton. If your symptoms are severe; a damp dressing may help. Find a soft cotton garment like a long-sleeve t-shirt or long underwear, soak it in cool water, wring it out, and then put it on. Wear a loose-fitting garment over the dressing. During the duration of the rash, activities that lead to unnecessary skin contact and sweating should be avoided.  Most contact sports - like football, rugby, and hockey - should be avoided altogether as it's hard to avoid touching and further irritating the skin. Exercises like aerobics, running, and weightlifting can be fine. However, sweating can be harmful to a skin rash so if you choose to participate find fast-drying workout clothing that does not have too much contact with the affected area.
Do not scratch your rash. Choose loose-fitting clothing. Refrain from conducting activities that irritate skin.