Continue writing the next sentence.

How to dress for hiking
Avoid heavy base layers if you plan on hiking in warm weather.
Long underwear is smart for colder weather, but it does not make much sense if you plan on hiking through the woods in the middle of summer.
Wear the right thickness of thermal underwear for cool weather.
Thermal underwear comes in light, mid, and expedition weights. The colder the conditions and the longer you plan on being out in them, the heavier you should go with.