Off-topic, but if you're inside a building or outside the 1/2 mi central radius, you won't be vaporized. At which point you want to make sure you are protected from the fireball which is coming; ideally you go inside a solid structure. This will protect from 3rd degree burns from the fireball, from the air pressure wave coming afterwards (hence solidity to prevent collapse), and from the highest radiation.

https://www.vice.com/en_us/article/qjd8bq/how-to-survive-a-n...