https://www.nasa.gov/audience/foreducators/spacesuits/facts/...
Edit: This says it can actually be done in five minutes in an emergency if one's willing to skip every safety check, but getting an unresponsive person into one seems like surely it would be more of a challenge -- particularly if the "helper" was wearing a spacesuit himself. Those things are awfully restrictive! And I would wager it's not a scenario they practiced.
https://airandspace.si.edu/stories/editorial/how-do-you-put-...