[CryptoPunk]

12 µSv in two 500 ms bursts is very different 12 µSv spread out over 1 hour of flight time.

The difference in intensity is 3,600 fold. It's the difference between being subjected to 1 hour of 30 degree celcius heat and 1 second of 108,000 degree celcius heat.

[hunter2_]

To bolster your argument: only the Kelvin scale is eligible for multiplication operations, so 30C * 3600 = 1,091,067C when converting to K and back.

On the other hand: I expect 500 ms of such extreme heat would instantly kill a human, although I'm having a hard time finding an answer for such a short time scale. Since X-ray imaging doesn't instantly kill, it's apples and oranges, but point taken.