Good find.  It’s the pleats at centre front and centre back that make it look like a skirt. 

@Flobear funnily enough I’d been searching for exactly that for a couple of weeks. 
I came across these which seem to be very popular.  There are several pattern hacks for them too on her site. 
https://helensclosetpatterns.com/product/winslow-culottes/

But this one looks the closest to a skirt in my opinion.  I think it takes a lot of fabric but has a pleat at front and back which gives the real skirt appearance. 
https://megannielsen.com/products/tania-culottes-sewing-pattern
And there is a pattern hack I came across for elastic parted waistband
https://blog.megannielsen.com/2017/09/elastic-waist-back-side-seam-pockets-tania-culottes-tutorial/

Another one
https://oliverands.com/shop/digital-girl-friday-culottes-sewing-pattern.html

In the end I made my own using my trouser crutch and drafting from there.  A nice soft drapey fabric works well. 

Very interesting. 

@UttaRetch do you have memory foam!

@sewingj think it’s this one.  Nice and compact.
https://www.spencerogg.com/product/compact-accordion-wallet-pdf-sewing-pattern/

Hurrah, I'm not alone.  Most people look at me weirdly when I say only white bedding will do!

  . White duvet covers too. And only white towels.  Makes choosing easier.  And you know when they’re dirty!   I saw some hotel inspector on tv say hotel towels should be white for that very reason. 

Another one that sleeps with nothing on.  So much comfier.  Pure cotton sheets and like @Missie they have to be white.  Big windows will be open all night when it gets hot later this week.  We have a 1 tog quilt which is useful.  But if it’s very hot then it’s just the duvet cover. 

Something we have found works well is to open up the loft hatch.  If we have a good summer it can be open for weeks.  As hot air rises it seems logical really. Can’t remember where I heard it but does make a difference.  We also take down our curtains and put up a pair of voiles.   It lets the air through a bit more.  Alternatively pull the curtains back some way to allow the air in.  As we're on our own we also have the bedroom door wide open.  And the door to the en-suite is open and the window is open in there. 

Hope that gives you some ideas.  It’s miserable when you can’t sleep and you’re hot.