This is a problem I usually come across with my stories. I often worry about whether the plotlines I introduce are realistic or not, and it's usually something that can't be solved with a simple Google search.
One of the characters in my story, a young boy, is locked up in a cell and is on the verge of starvation before he's rescued. However, the rescuers are unable to get him to a hospital, but they are able to supply him with food. Unfortunately, the boy is at a point where he would need intense medical attention to recover. Giving him food only delays his death, hopefully until they can find help before he dies.
How can I know how long the boy could survive under such circumstances? How can I find out what would be realistic in such a situation?
This is a pretty simple example, but I've got a lot more, where I just can't simply look up the answer. I could just make something up, even if it doesn't make sense later, but I'd like for it to be in the realm of possibility.