Although these are for men, they work just as good for females. I am usually a large in the women's sizes, but the medium in men fitted perfectly. The only problem I have with these is that the sitching around the waist is coming apart after the 2nd wash, I liked them because they stay close to your skin and don't feel bulky and they do keep the cold out. Used them for a trip to NYC and Washington DC and they came in handy.
The Kenyon Men's Polypropylene Fleece Thermal Underwear are exceptionally warm and comfortable. My boyfriend works outside and up high in cooling towers and I purchased the full set for him. He loves them, I liked them well enough to purchase a set for myself. The only downside I can find about this product is they are hand-wash and drip dry, but the effort is well worth the performance!