It's time to get the kids tucked up in bed - Santa is set to leave the North Pole shortly and as everyone knows, he only delivers presents to good children who have already gone to sleep.
Several organisations keep track of exactly where Santa is via GPS, among them the North American Aerospace Defence Command which tracks his flight path as he traverses the globe. The tracker starts at 8pm.
Kids across the world can call NORAD to find out exactly where Santa is at any time, whether they're on the naughty or nice list and whether he got their present requests.
Despite having to deliver more than 1 billion presents, Santa is expected to turn up on time, get every request right and get home in time for tea.
But after centuries of living an unhealthy lifestyle, binge-drinking and pulling all-nighters, medical experts fear the jolly fat man is on the verge of collapse and it will be a miracle if he makes it around the globe tonight.
The UK's Royal College of GPs said it was not known whether St Nick was registered with a doctor but he was "probably due a checkup".
They highlighted his obesity, as tonnes of mince pies and millions of litres of milk and sherry have taken their toll.
"Obesity can lead to numerous health problems, such as hypertension, diabetes, fatty liver disease, and cancer," the college warned. (It can also make it hard to fit down the chimney.)
Santa was also at risk of developing gout, a painful joint condition that could lead to kidney stones and make climbing on roofs excruciating.
The annual binge-drinking of sherry on Christmas Eve means Santa would likely be considered an alcoholic, the GPs said.
"If left untreated, this could lead to immune system dysfunction, cirrhosis of the liver, pancreatitis or brain damage, not to mention bad skin and strong body odour," they warned.
They also fretted about his mental health.
"It is not known if Santa has a companion at home, so he could be at risk of feeling lonely. Loneliness and social isolation can be just as bad for his health and wellbeing as having a chronic condition and it is unlikely there are many community groups he could join in the North Pole."
Work stress affects us all, but Santa is under particular pressure right now. His shift pattern and crossing multiple-time zones mean he's likely to exceed the eight-hour work day, not to mention sleep deprivation and drink driving making sleigh-driving risky.
"Not getting enough sleep can lower immunity, fertility, and make it harder to shift excess weight," the college said.
Santa is also vulnerable to disease - from exposure to millions of children's germs to contracting Lyme Disease via ticks that have hitched a ride on the reindeer.
One insurance company ran the numbers to calculate the bill Santa could face if he didn't take out travel insurance, particularly if he or the reindeer come down with an illness in a foreign country.
Reindeer's natural diet consists of leafy greens like mosses along with mushrooms and other fungi. The occasional carrot is ok but if they gorge themselves on cookies they could require medical assistance. If they're in the US Santa could be up for a hefty $25,000 charge to cover costs.
And if Santa develops an allergic reaction to pine trees while passing through Switzerland, an emergency callout and hospitalisation could cost him a steep $12,000.
If Santa were to misplace his travel documents they could cost $3000 to replace, while if his smartphone gets nicked while in Nice he'll need a cool $1,500 to replace it at short notice.
It has been calculated that Santa will deliver gifts to 1.6 billion children tonight.
If any fall overboard or get stolen by the Grinch, insurance would in theory cover buying their replacements.
Allianz spokesman Will Ashcroft said Christmas is a "perilous" time for holiday makers as people let their guard down, whether driving on the roads or going through airports.
The New Zealand branch of Allianz is expecting 1,200 claims over the festive period, at an averate of $900. The most common will be to do with lost luggage, but they are also expecting at least three repatriations.