It has been getting very cold at night and the only time I have to walk each day is late at night, after work.  I hate wearing thick cotton sweatpants, as they feel very uncomfortable, particularly when I start sweating.  Wearing these thermal leggings underneath my looser striped athletic pants keeps warm, comfortable, and importantly, feeling dry.  My only nitpick is that my athletic pants sometimes catch on these, as they are made of a similar material.