1. On Parris Island, we had ponchos to wear in rainy weather, but were never allowed to wear the hood. Reasons unknown.
2. Wearing the hood obscures one's peripheral vision, and hearing, to an extent.
Reason #2 was probably why reason #1.
I put my hood up when it’s very cold to run out to the car or into a store and then take it down.
Why?
I cannot be fully situation-ally aware with it up.