Gary Cooper hops on his bicycle [Photo/PowerHouse Books]

Oscar Wilde once said, "Lookinggood and dressing well is a necessity. Having a purpose in life is not." However, summer is a particularly challenging season, sartorially speaking. As the temperature rises, there's a temptation to sacrifice elegance for comfort.

But think twice before grabbing your favourite T-shirt and slipping into some old sneakers. Marc Lauwers, the head of Lanvin's bespoke shirt workshop, knows his stuff about the sartorial rules. When asked how to endure the heat and humidity with elegance, he answers: "A true gentleman doesn't care about the cold and heat – he is above climatic contingencies and looks good whatever happens." After a dramatic pause, Lauwers adds, "If you can't help but feel warm during summer, there are some appropriate outfits that may help. But let's be clear: tank tops and shorts aren't an option."

Smart summer style starts with lightweight clothes that breathe well and keep you cool. "Silk, for example, dries very fast and insulates from both heat and cold," says Lauwers. "Once you've tried silk shirts, it's hard to go back to basic ones." For suits, linen is the ultimate summer fabric – and what's more dashing than a tobacco linen suit paired with a light shirt?

Yet, linen tends to wrinkle easily and its typical laid-back look may not be suitable for every workplace. "Cotton-linen is a nice alternative: it's easy to care for, needs little ironing and wonderful to wear when the temperature soars," says Lauwers. And surprisingly, one of the best fabrics for summer is wool broadcloth, which stays cool and fresh while looking more formal. "Unfortunately, wool feels a bit crispy and not everyone appreciates it," he says. "The truth is that you should try many fabrics to figure out which one you prefer."

As warmer weather approaches, sleeves become a controversial topic. To roll them up or not: that is the question. Historically, rolling up your sleeves was a sign of a man going to work – or to fight. Showing off your biceps is still a sign of manliness, but if you simply want to be in the happy-hour mood, don't roll your sleeves over your elbow. "In my opinion, no sleeve should be rolled up," says Lauwers. "It's commonplace to say that rolled sleeves cool one down, but it's an illusion. On the contrary, once rolled, the fabric is thicker and warms you just where you're supposed to sweat the most: at the crease of your elbow flexure."

Lorene (Donna Reed) confronts Prew (Montgomery Clift) at a party in From Here to Eternity (1953) [Photo/John Springer Collection/Getty Images]

When asked about short-sleeved shirts, Lauwers says, "They don't deserve the bad reputation they have and can be a good option. Trust me, when one goes to the beach, a nice short-sleeved shirt always looks better than a T-shirt. But please, leave your tie at home and don't wear a jacket over it – that would be a terrible fashion faux pas." There are two other key tips to stay cool in a shirt: wear it over your trousers and choose one with a convertible collar that elegantly folds back into lapels when worn in an open style. Alternatively, why not pay tribute to 1953's From Here to Eternityand don a vintage Hawaiian shirt?

When deciding on the best pair of trousers for summer, make sure that its shape lets the air comes through. Slim trousers promise you long and sweaty days. "Concerning the fit of trousers, summer is the season for large pleated trousers, preferably high-waisted: they are way more flattering than the hipster ones that dramatically shorten your silhouette," says Lauwers.

And don't forget to keep your socks on, gents – summer and winter alike, they're indispensable. Summer is the perfect time to set aside those grey and black ones and to inject a little colour in your look; green, orange or even pink socks are welcome. "Do I need to mention that one must wear long socks?" says Lauwers. "They don't keep one too warm and hide leg hair when one sits comfortably on an armchair."

Last but not least, put a nice hat on before heading out in the heat. A Panama hat will instantly upgrade your summer look while protecting you from the blazing sun. Now you're good to go, gentlemen.