I recently saw a comment chain about nuclear bombs, and that led me to thinking about this. Say there is a nuclear explosion in the downtown of my US city. I survive relatively fine, but obviously the main part of the city has been destroyed, while major zones extending from the center were also badly damaged. What would be a good response to (a) survive and (b) help out the recovery effort?
The first rule is don’t become another casualty.
Hunker down for a few days, iirc the most dangerous radiation will decay in the first few days. You don’t want the ash on your body. Fill your bathtub/whatever else with water to drink and ration your food.