Also worth noting; Mechwarriors tend to dress down in the cockpit. 

Unless specified otherwise, mechwarriors have a neurohelmet and a cooling vest, which is rigid, bulky and so forth. Mechwarriors in a cooling vest tend to do without much in the way of other clothing because of the heat factor. There are cooling suits, and DCMS mechwarrior combat suits that are full body rigs, but they are expensive and hard to find. 

An example of mechwarrior dress can be found in this gallery: [url=http://www.sarna.net/wiki/Uniforms]