Motorsport is a lot safer these days than it used to be, but there are still certain events where competitors set-out in the knowledge that, if it all goes wrong, there's a good chance they won't come back. I'm thinking, for example, of the Isle of Man TT motorcycle races, the Carrera Pan Americana, the Dakar Rally - and the truly terrifying Pikes Peak International Hill Climb.
Staged once a year outside Colorado Springs, the 'PPIHC' has been going since 1916 when it was first held to mark the opening of 'the world's highest highway', a $283,000 road built and paid for by local tycoon Spencer Penrose who, even at the turn of the century, is said to have been earning $1 million per year from his enterprises in everything from life assurance to gold mining.
The first winner of what came to be known as 'the race to the clouds' was 22-year-old Rea Lentz who took-on the 12.42 mile course and its 156 turns in his Romano 'Demon' Special, finishing in a time of 20 minutes and 55 seconds.
A century later, French rally ace Sebastien Loeb still holds the record he set three years ago with a time of eight minutes and 13 seconds driving a Peugeot 208 T16 that was specially built to tackle the climb at a reputed cost of Euros 1 million.
It is difficult to convey just how frightening this event is: on those 156 turns, for example, there are just seven lengths of crash barrier. But, on the vast majority of the course, there is nothing at all between the side of the road and drops of hundreds of feet either side - approaching many of the bends at racing speed, for example, all a driver sees ahead is clear, blue sky with little else available for orientation.
But sometimes the sky isn't blue at all - it can be obliterated by dazzling sunshine, or covered in angry grey storm clouds which often herald some of the most fearsome lightning strikes in the U.S.
The event is capped at around 130 competitors, all of whom must apply to be invited to take part in one of the many classes, which encompass everything from highly-tuned quad bikes to sidecar racing outfits and from V8 muscle cars to the latest electric and hybrid vehicles (Honda fielded several examples of its new NSX supercar this year).
And it's that all-round unpredictable nature of Pikes Peak that makes it one of the ultimate challenges to man and machine, a rare event in which a racer can leave the start line in 30 degree heat but end-up sliding about on ice half-way up.
All-in-all, therefore, the perfect event to encapsulate the thinking behind TAG Heuer's 'Don't Crack Under Pressure' campaign - which is why the brand's latest motorsport association is as Pike's Peak's official timing partner.
This year's centenary race was seen as something of a test event for TAG, which supplied the countdown clocks at the bottom of the hill, from which racers build-up to a 'flying start' a few hundred meters further on.
According to TAG's ultra-accurate timing devices, the outright winner of this year's centenary run was Romain Dumas who arrived fresh from his victory at the Le Mans 24 Hours the previous weekend to win the 2016 PPIHC in a time of 8 minutes, 51,445 seconds - despite having to make the run using an untried engine that he and his team had stayed-up all night to fit after their original blew up.
So there was more than a bit of pressure there. But did Dumas crack?
Front picture: Romain Dumas crosses the line