Solar Radiation Hazards to Humans from Geomagnetic Storms

Geomagnetic storm effects

Radiation hazards to humans

Intense solar flares release very-high-energy particles that can cause radiation poisoning to humans (and mammals in general) in the same way as low-energy radiation from nuclear blasts.
Earth's atmosphere and magnetosphere allow adequate protection at ground level, but astronauts in space are subject to potentially lethal doses of radiation. The penetration of high-energy particles into living cells can cause chromosome damage, cancer, and a host of other health problems. Large doses can be fatal immediately.
Solar protons with energies greater than 30 MeV are particularly hazardous. In October 1989, the Sun produced enough energetic particles that, if an astronaut were to have been standing on the Moon at the time, wearing only a space suit and caught out in the brunt of the storm, he would probably have died; the expected dose would be about 7000 rem^{[citation needed]}. Note that astronauts who had time to gain safety in a shelter beneath moon soil would have absorbed only slight amounts of radiation.
The cosmonauts on the Mir station were subjected to daily doses of about twice the yearly dose on the ground, and during the solar storm at the end of 1989 they absorbed their full-year radiation dose limit in just a few hours.^{[citation needed]}
Solar proton events can also produce elevated radiation aboard aircraft flying at high altitudes. Although these risks are small, monitoring of solar proton events by satellite instrumentation allows the occasional exposure to be monitored and evaluated, and eventually the flight paths and altitudes adjusted in order to lower the absorbed dose of the flight crews.^{[citation needed]}

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Geomagnetic storm - Wikipedia, the free encyclopedia

So, though this might change over time the most hazardous thing for any of most of us to do during a Geomagnetic storm is to be flying in a plane 30,000 to 40,000 feet in altitude near the poles of the planet. But like it says the flight crews will take on the most radiation(because of the number of times they are in the air) and what the passengers get will be mostly negligible. However, I must say that the effects of "Brain Scrambling" would be similar to if I had about 2-6 packs of beer during the next two days after flying when I flew on the 8th during a Geomagnetic storm that I didn't know about when it was occurring.  (And I usually don't drink because I'm mostly allergic to alcohol).  So, I was greatly affected by the first exposure and was uncomfortable the first night of the second blast of Geomagnetism generated by the sun. 

However, it is my belief that most humans can adapt to these types of Geomagnetic storms up to a point. When that point is reached I think we will all know it whether that is tomorrow or 500 years from now.