I assume you don't actually mean by "saving someone" what I would ordinarily assume that phrase to mean (e.g., take steps to keep their heart beating and their lungs pumping and their brains working and so forth), but rather some specialized understanding of "save someone" like preserving their neural patterns in anticipation of subsequent implementation of those patterns in a body. But I'm not entirely certain.

If I'm wrong, can you say more about why saving such a person in that more general sense is worth doing?

If I'm right, can you say more about why it matters whether they signed up for cryonics or not? For example: if you had the ability to cryopreserve my neural patterns the instant my heart permanently stops beating, would you do so if I wasn't signed up for cryonics?