Now I may be a bit past all this, but when I was taught to fly it was continually stressed that when flying, you should be wearing sturdy lace up shoes/boots, a long sleeve shirt and long pants both made of natural fibres.
Nothing to do with a dress code, simply a tiny pice of insurance should the unthinkable happen. Even if this were to aid a little in survival it would be worth it!!
Cheers, HH.
PS: Now I wonder why military, medivac, coastwatch and a whole plethora of organisations wear full length overalls and boots?