Ahhh mama, rashes during third trimester ay common talaga, ang hormones natin ay naguguluhan haha! A few of us moms had the same experience, and honestly, it's worth checking with your OB para sure kung anong type ng rash kaya niya ma-prescribe ng tamang cream (sometimes it's heat rash, sometimes pregnancy-related skin changes). In the meantime, light cotton clothes, stay cool, and avoid products na mabigat sa skin, some of my friends swear by gentle, pregnancy-safe moisturizers kasi sometimes the itching gets worse pag dry ang skin talaga.