A 35-year-old Russian skater fell five metres from a ring system onto the ice and was airlifted by helicopter to hospital - Lausanne Police have said "her life is in danger".

Although the ceremony is indoors, organisers have advised spectators to dress in warm clothing for the sold out event, but hardly expect the thermometer to dip quite as low as it did at either Innsbruck 2012 or Lillehammer 2016, which were both held outdoors.

Details of tomorrow's ceremony remain a closely guarded secret. 

We do know the theme is "Home" and is expected to feature seven elements of Olympism.

The design of the cauldron is being kept under wraps, but it will be fired from sustainable wood chips.

Although Youth Olympic ceremonies include many moments familiar to watchers of their Olympic counterparts, they are also deliberately distinct.

This is reflected at the start of proceedings, when the mass of competitors make their entry and take their places in the stand to enjoy the show.

In the parade of nations, each team is represented by a single flagbearer. 

The first one will be Greek to honour the home of the Ancient Games.

This is a tradition which began in 1928, even though Greece did not compete at the Winter Games until 1936.

Organisers at the Youth Olympics are always acutely conscious of the "target audience", and this is visible in the way the Opening and Closing Ceremonies are designed.

The life span of the YOG has coincided almost exactly with the rise of social media.

At Innsbruck 2012, the ceremony guides, on what was quite literally a social media platform, were DJs Bass T and Olympia - the music was a mix of hip-hop and Tyrolean dance.

The ceremony took place in the vast ski-jumping bowl at Bergisel - 1980 downhill ski champion Leonhard Stock left the crowd gasping by delivering the flame down the ski jump.

Three cauldrons burnt for Innsbruck. 

Egon Zimmerman had won downhill gold when Innsbruck first staged the Games in 1964, Franz Klammer's golden year was 1976, also in Innsbruck.

A third bowl was added, lit by Youth Olympian ski jumper Paul Gerstgraser.

The three flames burned for one night only.

A smaller, simpler cauldron was relocated to the town centre for the remainder of the Games to reflect the environmental message.

It was a similar story at Lillehammer 2016. 

Following the example of her father, who had done so in 1994, Princess Ingrid Alexandra climbed to the top of the giant cauldron to ignite a flame. 

Post-ceremony, the flame was taken to Sjogg Park in the centre of town, where it burned for the remainder of competition.

A predominantly volunteer cast of some 800 had done their best to make the crowd forget the bitter cold.

The theme this time was one person's journey through sport via 16-year-old Eilif Hellum Noraker, already an established actor with a promising future, who was chosen as ceremony navigator.

"The boy dreams that he will be a world famous sportsman," said ceremony director Sigrid Strom Reibo.

His struggles to overcome problems along the way were related in the show.

If previous ceremonies are a guide, expect this one to include young people who have taken the initiative in their communities.

There will, of course, also be an Olympic oath. 

It was at the Youth Olympic Games that the innovation of an oath for coaches was first introduced. 

This was subsequently adopted at the Olympics themselves, along with participation by a representative of athletes and judges.

The oath itself celebrates its centenary this year, although the wording has now changed to include a reference to doping.

It is accompanied by another piece of ceremonial from 1920.

The five-ringed flag was first raised above an Olympic Games that year.

Youth Olympic tradition calls for it to be trooped in by great champions of the past, and symbolically handed to young athletes representing the future.

The music which accompanies the raising of the flag is the oldest Olympic symbol. 

The anthem composed by Spiros Samaras was first heard at the 1896 Games in Athens, thus providing a perfect link from the first Olympiad of the modern era to the latest Youth Olympic Games.