The day I melted on Murray Mound

"No mercy Andy, make it quick", shouted the puce-faced man to my left, before emptying a £3 bottle of official Wimbledon mineral water over his head. They were common sentiments on Murray Mound as Britain's great tennis hope strode on to Centre Court at 2.16pm in 41C of merciless heat.

About 5,000 people crowded on to sport's most famous hillock yesterday, anticipating an epic battle of brains and brawn similar to that played out between Murray and Stanislas Wawrinka on Monday night, in the clammy crucible created by the debut of Centre Court's £80m retractable roof.

In the end, the 22-year-old Scot contributed considerably less sweat to his triumph than I did.

After securing one of the prized spaces in front of the giant television screen, it became clear that the same etiquette which applies to watching tennis on a court (no one moves until a break in play) also applies among the mound's Murray Maniacs.

Alison Murphy, 43, an estate agent from Brighton and a mound resident for the last three tournaments, set out the rules: "Cheer lots. Wave your hands when they show us on telly. But don't even think about moving until the end of the first set."

As Murray trotted through the first set in his quarter-final against former world No 1 Juan Carlos Ferrero, aka the Mosquito, I sat trapped in my three square feet of burning viewing terrace, not knowing whether to cheer another forehand winner or open a bidding war for my neighbour's second bottle of ice-cold dousing water. As the mercury nudged 30C (and hit 41C on court), a £20 offer was rebuffed. "Add a zero and we can talk," came the response.

The mysterious disappearance of 28 members of Wimbledon staff with supposed flu-like symptoms seemed suddenly explicable – heat wave aversion.

Mercifully, the man from Dunblane duly obliged the entreaties to be quick and averted a human hog roast on his eponymous hill. After one hour and 41 minutes of increasingly swashbuckling tennis, Murray hit an unplayable serve at 4.57pm and in so doing played his way into his first Wimbledon semi-final, beating Ferrero in straight sets 7-5, 6-3, 6-2. The Mosquito, so-called for his sinuous speed, had been swatted.

On the mound, the woman behind me opened a molten Penguin and calmly drank its contents in celebration. St John's Ambulance said it had treated 117 spectators for heat-related ailments. Perhaps unsurprisingly, it was the highest figure so far this Wimbledon.

Inside Centre Court, the onward march of Murray had attracted the traditional range of celebrity tennis fans.

Kate Winslet and her husband, Sam Mendes, watched largely impassively from the royal box. Miss Scotland 2009 cheered vigorously at almost every opportunity. The fact that the newly crowned Katharine Brown, 22, was a classmate of the star at primary school in Dunblane and his mother once coached her at tennis may have had something to do with her enthusiasm.

The man himself, however, maintained his trademark levelheadedness in the face of the gathering tidalwave of expectation from the hoi polloi on the hill and the glitterati that Britain is just two matches away from its first men's Wimbledon champion in 73 years. Two tickets for Sunday's final were last night being offered on eBay for £6,950.

As well as receiving messages of support from the Queen and Sean Connery, Murray said he had received a note from Cliff Richard yesterday. And after neatly sidestepping a question about whether he would support England or Australia in the Ashes, Murray declared himself unbothered by the weight of expectation upon him. "It doesn't make any difference [to] the way you perform, the hype. If you ignore it, you don't realise it's happening," he said after the match.

On the mound, there was perhaps a sense that the Anglo-Saxon enthusiasm for the once prickly Scot was yet to burst into a full-scale love affair.

Amid the waving Union Flags, there was only one banner with a full-blooded declaration of passion. It read: "Sue Barker will you marry me." Then again, perhaps, like me, the true fanatics were too busy sprinting to the shade and a water tap to care.