CTA-50.......... Includes instructions on what clothing and equipment is authorized for a given location. i.e. climate.
http://armypubs.army.mil/doctrine/DR.../cta50_900.pdf
tm 10-227 fitting of uniforms.... The section on shoes and boots and how to check for fit is helpful, if you didn't already know.
http://www.liberatedmanuals.com/TM-10-227.pdf