Einsteinium and Fermium were discovered after the first hydrogen bomb was detonated in the fallout. Much more radioactive than Cobalt 60. Much of the fallout from a fission device emits hazardous levels of radiation but not necessarily lethal. A Fusion device transmutes everything to radioactive isotopes. The problem is collect enough fallout in one place and yes, one can receive a fatal dose. Yes, chemical and contamination can be mitigated with barriers of waterproof clothing. However if fallout accumulates in one place you can get a fatal dose of just radiation.Staying safe from fallout is about keeping radioactive dust/ash off of you which can, for the most part, simply be brushed or washed off, it's not about radiation itself which you cannot get away from. The whole idea is to minimize the amount of radiation absorbed by ensuring that you are not covered in radioactive materials.