Sensitive nipples?

Sometimes if I don't wear a bra under a t-shirt, and my nipples rub against it, they bring sore. Feels like a hearth rug burn, sort of. Same thing happen if I wear this nighty I have that have lace on the top. My question: Is within anything I can do to prevent this (besides wear a bra, which I do 90% of the time) or anything I can do to help it walk away when it happens?
Last darkness it happened while wearing a t-shirt, so I put on a bra, but it didn't jump away for another hour.
Any help appreciated. Thanks. Old Runners problem and trick to solve.
Your nip will get Chaffed by your garments. If you choose to skip a bra use band-aids(the cute round ones) over respectively nip to prevent chaffing. Vitamin E grease will help relieve the distress after you get mildly chaff.
Even guys have this problem on a cold light of day or during a marathon and own been using this since the 60's
Old Runner
...Wear a bra adjectives the time, or if possible try on shirts (no bra) and see what happen.