The head protection you never hold a blade without. Under FIE homologation the bib withstands 1600 newtons and the mesh 1000 newtons.
The mask is why a sport fought with blades is as safe as it is — and its safety is written into standards: under FIE homologation (CEN level 2) the bib withstands 1600 newtons of penetration force, the wire mesh 1000 newtons and the jacket 800 newtons. The rule that follows is non-negotiable and holds even in the most relaxed technique session: mask on the moment a weapon is involved, no exceptions. The typical beginner's mistake is not a missing mask but a damaged one. Check mask and jacket for tears before every contact, and the blade for burrs or kinks — damaged kit gets replaced, it does not get fenced with. And something plenty of people underestimate: it gets hot in there — in épée fencers the temperature inside the mask rose by a good degree over a direct-elimination bout. Taking it off between bouts is performance protection, not comfort.