The autonomic nervous system (ANS) functions to mobilize energy and deliver oxygenated-blood to the body. The ANS changes during sleeping and waking states, postural changes, and physical movement. Moreover, ANS changes occur during mental states such as stress, emotion, cognitive, and motivation. This document provides an overview of some of the more commonly used measures in stress studies that can be obtained relatively non-invasively. We describe the process of obtaining ANS responses including technological requirements for lab and field experiments, and the specifics of obtaining, scoring, quantifying, analyzing, and interpreting ANS responses.