You’ve discovered new units, Grays (Gy), Sieverts (Sv) and their smaller versions; uGy, mGy, uSv, mSv. Here is a poster from the excellent xkcd site that explores examples of the different levels of equivalent dose.
Click on the picture for a larger version.
Notice that the scale changes as you move through the poster from blue to green to red.
The dosimetry topic is very short and comprehensively covered at BBC Bitesize.