As Olympians toiled in 36 degrees Celsius last week, the liberal slopping of sunscreen helped competitors and spectators alike avoid burning under the French sun.
Little known to most, they were benefiting from research undertaken in Australia, where one of the world's first commercial sunscreens was manufactured — complete with a splash of French perfume to make it smell "delightful".
University of Adelaide science graduate Milton Audley Blake cooked up this invention in his kitchen in 1928, using saucepans, hand scales and a kerosene room heater.
"He and a couple of his mates from the university decided they would set up a bit of a side hustle," Australian National University medical historian Dr Laura Dawes said.
"Launching what was really a pharmaceutical beauty products company."
Milton had the idea to create a sun-protecting cream after reading trade publications from Germany that mentioned an organic substance that could filter ultraviolet (UV) light.
He experimented and created a formula to incorporate phenyl salicylate into a topical cream formulation.
"By today's reckoning … it would have had an SPF [Sun Protection Factor] rating of two, so not superb, but better than nothing," Dr Dawes told ABC Radio Adelaide.
Dr Dawes said another of Milton's friends invented a machine that would fill tubes with their sunscreen, only it was difficult to use, with the young men at one point trying various techniques, such as "sitting on the pistons", to try and make it to work.
"Eventually they got the tubes filled and Milton said, 'Oh, I've forgotten to put the perfume in,'" Dr Dawes said.
"They'd bought some very expensive French perfume to put in this product, so they had to squeeze it all back out of the tubes again and have another go the next night.
"It must have been quite nice and you would smell delightful after using it."
An Australian first
German physician Dr Paul Unna had developed a sunscreen from chestnut extract and sold it in 1910, but Milton, who had started signing his name as H. A. Milton, began selling "Hamilton's Sunburn Vanishing Cream" in 1932.
It is believed to be the first commercially manufactured suncream product in Australia.
"Interestingly enough, when they first marketed this product, they advertised it as something where you could safely tan if you used it," Dr Dawes said.
"We now know that browning itself is a sign of sun damage. Unfortunately, you can't have a safe tan."
She said Milton and his friends tried selling their cream to Adelaide department stores without success.
So, they started going from house to house, expanding their range to include household products like fly spray, indigestion powder, bath salts and antiseptics.
"Other players entered the [sunscreen] field in the 1930s and 40s, so they were getting a bit of competition but the company was doing pretty well," Dr Dawes said.
In the 1970s, University of Queensland researchers Gordon Groves and Don Robertson undertook tests on mice — and on their colleagues — to develop a ranking system for a sunscreen's effectiveness.
They printed the results in a newspaper for the public.
Australian Standard AS2604 testing based on their research came into play in 1986.
Today, sunscreen is ranked under the SPF system, which measures how long it will take for your skin to burn.
For example, SPF50+ means it will take 50 times longer for your skin to burn than it would without sunscreen.
"And nowadays, all of our sunscreens filter both parts of the UV spectrum [UVA and UVB]," Dr Dawes said.
"That's in part because of research done by Gordon Groves and Don Robertson, who discovered it wasn't just UVB that caused burning, but UVA as well.
"So in Australia, we get broad spectrum sunscreens that filter for both parts."
Finding broad spectrum
Before Milton passed away in 1977, he gave the role of managing director to his son, the late Richard Milton.
"In the 1980s, Richard heard of a new sunscreen ingredient that filtered out UVA, so the company formulated the first broad-spectrum sunscreen then," his wife Margaret Milton said.
"So, that was the first broad-spectrum sunscreen in Australia.
"Richard was also instrumental at the time in raising the need for SPF to go to 30 rather than 15, and then in later years, he instigated the change to make it an SPF of 50."
The family eventually sold Hamilton Laboratories in 2010, which had continued to operate from Flinders Street in Adelaide.
Margaret said Richard had collected everything along the way, historical documents, research findings, old documents, and even the minutes of the fledgling company's first meeting in 1932.
"I approached the State Library [of South Australia] and the wonderful staff there have taken the lot and are collating it and going through it," she said.
"That's a great relief to me and the family."
ABC