Tell her you love her. You won’t be harmed, even if she doesn’t feel the same.

Can you define “death” in the context of your question? I feel you might have referred to some forms of reversible coma.

Watch out! Generating CO2 in enclosed spaces might turn into a health hazard without monitoring it.

CO2 is also “heavy” and tends to sink, so watch out for pets as it could be deadly for them - https://en.wikipedia.org/wiki/Cave_of_Dogs

Have no expectation of finding a “magic pill” that (permanently) solves your problems.