A firewoman, perched on the back of a slow-moving float, hoses a cloud of mist over the fans at the roadside. Merci! they call back. Most return a grin and a thumbs-up, too. Under the baking sun in Carcassonne, as the riders arrive to sign on for stage four of the Tour de France, even a second of coolness feels like bliss. The float then trundles on, and the heat feels inescapable again. It blazes from above, rises up from the tarmac, and sears with each gust of wind, like a blast from a hairdryer. Visma-Lease a Bikes bus is nowhere to be seen its air conditioning unit has broken, and the driver has had to make an emergency trip to the garage. Their riders turn up to the start on their bikes, some in ice vests. It's a hopeful bid to fend off one of the harshest heatwaves France has ever felt. According to ProCyclingStats, Tuesdays stage was the hottest at the race since the websites records began in 2007: an average of 36.5C for more than four hours. At its worst, the temperature soared to 45C, so read the data on EF Education-EasyPost rider Alex Baudins GPS computer. Of course, hot weather on the Tour is expected riders prepare for it all year round but these numbers are extraordinary. And theyre set to continue. Its hot. Its definitely hot, Ineos Grenadiers Josh Tarling tells Cycling Weekly. The 22-year-old finished fourth from last on stage four, riding with a cracked rib suffered in a crash at last months Tour Auvergne-Rhne-Alpes. It hurts when I breathe anyway, he says. With the heat as well, obviously youre breathing harder and the pains catching up. It just feels airless. The fire brigade is on hand at the race to cool down fans. (Image credit: Getty Images)France has been suffering from the heat for around three weeks now. Public health officials announced there were more than 2,000 additional deaths in the country in June due to the soaring temperatures and even that, they added, was an underestimate. Its against this backdrop that, on the eve of the Grand Dpart in Barcelona in Spain, Frances interior minister gave local authorities the power to modify and even cancel stages in the event of extreme heat. If such a scenario were to happen, it would be a first in the races 112-year history. But with record temperatures, come serious measures. The effects of climate change have become an undeniable reality. Beyond stage threes finish line in Les Angles where fans were refused entry due to wildfires nearby Tom Pidcock gasped to regain his breath. I dont think Ive done such a hard race in such heat before; it was ridiculous, he told the TV cameras. It was like a war zone. I think we went through about 10,000 bidons today as a peloton. Drinking fluids is one of few ways riders can ward off heatstroke while exposed on the road. They wear ice vests before the stages, too, rely on stockings stuffed with ice cubes during it, and drink slush to try and lower their body temperatures from within. Outside his team bus at stage four's finish in Foix, Soudal Quick-Steps Jasper Stuyven bit into a fruit pastille lolly as if it were a chicken drumstick and he hadn't eaten in three days.Other cooling strategies are more sophisticated; Alpecin-Premier Techs riders took it in turns to visit ice baths inside a blacked out van behind their team bus after stage five in Pau. Similarly, UAE have been sleeping each night in smart mattress cover systems, which measure the riders core temperatures and cool the bed accordingly. And yet, Tadej Pogaar still complained of a full headache from the heat at the start of stage four. Jan Tratnik carries bottles for his Red Bull-Bora-hansgrohe team-mates. (Image credit: Getty Images)Lewis Askey, one of NSN Pro Cyclings key leadout men for Biniam Girmay, is one of those that tends to struggle in high temperatures. Im a lot better now than when I was younger, but Ive had really, really bad days in the heat in the past. Its like my body switches off a little bit, he tells Cycling Weekly.To help riders mitigate the heat, the UCI has allowed extra bottle hand-outs at the race. How many is Askey taking on during the stages? It depends if youre counting actually drank or chucked over my head, he says. Id probably say two or three an hour, and then a couple [over my head] every hour or so, and ice socks. Other riders, like Decathlon CMA CGMs Matthew Riccitello, are more used to the conditions. Standing unsheltered in 36C heat at the start of stage five in Lannemezan, he waves off his team press officer when offered an ice vest. Its not fun for anybody to ride in this heat, he says, but the American's from Tucson, Arizona, where its not abnormal to see temperatures tick into the forties. So far, Ive coped with it quite well, Riccitello says. I think just being from somewhere that is quite hot, I maybe adapt better. I dont know. Theres only so much you can do. And there, in that last sentence, lies the crux of the issue: the Tour de France is powerless to Mother Nature. If temperatures continue to rise, as climate experts forecast they will, the race could become less a show of sporting brilliance, and more a test of whoever melts the slowest. Lets just hope there are enough fire brigade floats to cool everyone down.