Do u hav to wear the full guthans to get its effect? runescape question?

reason y im asking this is im lvl 94 and im doin slayer and i have to slay cave crawlers inside the desert slayer dungeon. but when you go inside the dungeon you hav to wear a face mask and therefore i cant wear guthans helm. you knw the effect of guthans, its when you hit, and the amount of the hit also heals your hp, i think thats the effect (dont knw much about barrows armour).