That is like what the Iceni tribe in East Anglia did with a group of their tribesmen. Removed any comfort for them, brutalising them through beating et cetera to make them so mentally ill they went berserk on the battle field. These warriors went into battle without much clothing on, freeing them up and with mallets and axes. They were called Berserkers'.
Beserker is actually a Norse term, not British Celtic.
https://en.wikipedia.org/wiki/BerserkerAlso, it was common for Celts to fight wearing little or no clothing.
Devious, treacherous, murderous, neanderthal, sub-human of the West.