The alpine lake above sits at about 12,000 feet (3600 meters). You are on a backpacking trip with your friend near here. You are an experienced outdoors person and you have discovered that your friend is not as prepared for this adventure as you are. The weather this day started out comfortable around 65 degrees Fahrenheit (18 deg C) when you started hiking.

As you hike your body creates heat, you get warm and you start to sweat. Sweat evaporates off the body and carries heat away from us. This is an example of____