[lunchladydoris]

I see the article was published in 2014. Does anyone know if much more has come out of this since then?

[Arech]

I've just investigated this - yes, there are more papers published. Just google to Wim Hof's site and check a page about science (I'm not sure I should post the link). There's an chronological list at the end of the page. Most of papers are open access, but there's one blocked, so Sci-Hub would help as always.