Carbon monoxide detectors aren't just there because of natural gas appliances. They're also essential to protect people in cases exactly like you mentioned -- a temporary tabletop camping grill.

It's frightening to read about people who don't have CO detectors and put a combustion-powered generator in their house when the power (and thus heat) goes out in the winter. As of a decade ago the rate of CO deaths was around 400 per year in the US. Whatever it is now it's still terribly high.

For a sad time here's a random article from news.google.com when searching for "carbon monoxide generator" https://www.nbcdfw.com/news/local/2-Boys-2-Men-Dead-After-Ca...