the "second disaster": when people give useless items, or hamper rescue and relief efforts by getting in the way
Please, PLEASE, do not immediately send yourself to Houston or Florida, or donate clothes or food (actual humans have to sort them). As callous as it sounds, money is the best thing you can give.
https://www.cbsnews.com/news/best-intentions-when-disaster-relief-brings-anything-but-relief/