Both of the nuclear weapons used on Japan to end WWII were fission devices, which means they were not H-bombs. What is commonly called an H-bomb is a fusion weapon, which uses a fission device to create the environment necessary for nuclear fusion to occur. In other words, an H-bomb uses an atomic bomb as a fuze. The primary and secondary detonations occur in micro-seconds so it is not very apparent that two of them happened, but they did.
From the scattered news reports - all of which use incorrect terminology - I believe what happened with the Navy people is they flew through the plume of the airborne radioactivity released from the hydrogen bubble being vented at the Japanese nuclear plants. Thus, the helicopter crews were contaminated by having radioactive particles or more likely radioactive gas molecules (probably I-131) which being ionized had attached to the crews flight suits and exposed skin. This is the same process that happens to people with high Radon levels in their homes. The radioactive particles have an affinity to certain fabrics and will attach to them. They can be removed by simply waiting for them to decay, wiping the fabric, or just blowing air over the surfaces. As for skin and hair, a simple washing or showering with soap and lukewarm water will eliminate the contamination by releasing it's chemical bond with the skin or hair (or fabric).
One thing to note - people don't have radiation on them. Radiation is energy. People have contamination on them, and the contamination contains radioactive particles which emit radiation in various forms.