A sticky, heatwave can melt away the foundations of your working wardrobe in an instant.

Smart coats, lined tailoring and court shoes are a recipe for a stuffy day at your desk, but floaty fabrics can feel too informal for the boardroom.

Almost three quarters (73%) of women admit to putting extra effort into their appearance at work, because it gives them more confidence, according to a Pantene Pro-V survey, while a third confess to putting in outfit overtime because they think their boss or colleagues will take them more seriously as a result.

But being boardroom-appropriate and avoiding heatwave hazards at the same time can be tricky.

Make a few cool styling tweaks, however, and your wardrobe will work harder in the heat. Designer Tabitha Webb (www.tabithawebb.co.uk) shares her top tips for summer wardrobe staples that won't break the office dress code.

LAYER UP

With cloud cover and unexpected showers, heatwaves are rarely a constant temperature from 9-5, so be prepared with a light top layer, like a shirt, that you can throw into your work handbag.

Webb says: "If you are lucky enough to have air conditioning in your office but it's boiling outside, layering is the answer to your cool-to-hot problems. A lightweight knit or blazer should do the trick, so you can strip off as soon as you walk out of the door."

BE BRIGHTER

Dark colours absorb heat - meaning you'll feel hotter in them - so make heatwave season the time to brighten up before you're back in autumnal shades. Choose a smart summer dress in a block bright or pastel.

"Keep the shape simple," Webb advises. " Have a clear understanding of the silhouette that suits you and stick with it. Look for lightweight fabrics, such as silk or cotton - I personally also love bright tweed in the summer for an officewear twist."

ARM EXPOSE

A strapless dress is perfect for a beach break, but can look unprofessional in the boardroom when only your top half is exposed. Keep a standby lightweight blazer on your chair to instantly smarten up an outfit.

"Think about what meetings you have that day and dress accordingly," Webb suggests. "A good rule of thumb is to ensure your hemline sits just above the knee and that you have cap sleeves on your tops and dresses so your arm is exposed but looks smart."

FEET FIRST

When temperatures soar, avoid closed toe shoes and pointed pumps, which can make your feet swell. Switch to footwear that lets your toes breathe. You can always keep a pair of courts under your desk for last-minute meetings with the MD.

"Open toe shoes or sandals are perfect for the office, as long as they still look smart, but don't forget your pedicure maintenance," says Webb. "Avoid beach shoes or flip-flops, unless you have a change of shoe with you."

NIGHT SHIFT

Accessories will completely transform your look if you're planning on going straight from stuffy boardroom to al fresco bar. Just choose a versatile piece that can be either smart or glam, depending on how you wear it.

Webb says: "Pick out a dress that can easily be worn with a pair of open toe courts and a jacket for the boardroom. Transform for evening mode by throwing on a pair of strappy sandals, ditching the jacket, and wearing a statement necklace or bangles."

GET THE LOOK

Newlywed Cheryl shows she's in Crazy, Stupid, Love with all-black everything. Get her sleek, croc-style clutch with Whistles' similar Rivington Chain Croc Clutch, £80 (www.whistles.com).

BUY IT NOW

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FASHION FLASH

:: COVER STORY

During July's heatwave, trench coats and wool overcoats topped the bestseller list at JD Williams. The launch of Lorraine Kelly's debut fashion collection promoted the surge in sales; the TV presenter's favourite stone trench (from £40) smashed brand records by becoming the fastest selling jacket in the store's 140-year history. "I am delighted at the success of the line, and it comes as no surprise that the stone trench is set to become the must-have item for autumn/winter because it was a fast favourite for me!" says Kelly. Her personalised AW edit, priced from £20-£150, is available now at JDWilliams.co.uk

:: RECESSIONISTA ALERT

School may be out for summer, but 'Back to School' ranges are already hitting the shops. Be prepared for the uniform kit-out at Sainsbury's. The value range includes boys' and girls' uniforms and bags, with prices starting from £1 for a unisex white crew neck t-shirt. Available now in more than 500 stores nationwide.