Live in subtropical climate and this product fits the bill for a lightweight casual, workout or yardwork and or pajama top shirt. If you are looking for something heavier this probably is not for you. Size is true to fit. I normally wear a large shirt and this shirt fits well not too loose but enough to allow for movement for your favorite workout routines. Fabric material is 100% cotton which breathes well unlike many of the polyester ones on the market  Follow laundry instructions cool or warm water and no high heat in dryer and it probably -it has for me - will retain its original purchase size.  Purchased many RUSSELL T-Shirts and overall happy with quality and value.