"The best way to prepare your skin for prolonged sun exposure is to get it in the best condition, in particular making sure it is well hydrated," says Sally Penford, education manager at the International Dermal Institute. "To minimise damage liberally apply SPF15 or above, making sure the product protects against UVA and UVB rays, at least every 90 minutes when you're in the sun."
But if it's too late and your skin is already showing signs of needing more TLC, our experts reveal how to combat the most common problems.
"There are several things that can contribute to your skin looking and feeling dehydrated in the summer - unprotected sun exposure is one of the biggest!" says Robin White, director of education at Philosophy. "In addition, being in and out of air-conditioning, or even sitting on a plane if you are going on holiday, can contribute.
"Exfoliation is key. Without it, skin can appear flaky and your moisturiser and treatments might be blocked from penetrating the skin. Try a weekly peel and a lightweight daily exfoliator, like Philosophy Microdelivery peel, £57, and the Microdelivery exfoliating wash, £20. For additional hydration, use a nourishing mask and take a moisturising facial mist along with you."
Start with an intensive serum before your moisturiser. Dove Spa Waterfall Intelligent Moisturising Serum, £35, targets the driest areas or Dermalogica Skin Hydrating Booster, £47.90, is intensive without being too heavy.
Then use a long-lasting moisturiser to treat your skin throughout the day. The Sanctuary Protective 24 Hour Moisturiser Lotion, £6, has SPF15 and is packed with protective antioxidants, while Lierac Hydro Chrono Extreme Balm, £33, boosts the skin's own hydration process.
If a cream is too greasy for you, SkinCeuticals Hydrating B5 gel, £32, contains hyaluronic acid to bind moisture to the skin while vitamin B5 repairs cells.
For added TLC, Caudalie Vinosource Moisturising Cream Mask, £21.50, contains hydrating essential fatty acids. If your skin feels dry during the day, top up with Clinique Moisture Surge Face Spray, £18, which binds moisture to the skin.
If you have broken the cardinal rule and got burned, Penford recommends products with soothing and healing liquorice, cucumber, chamomile and lavender, and Japanese alder to help repair UV-induced DNA damage.
A dedicated aftersun is ideal, or try Elemis SOS Emergency Cream, £48, with willow, myrhh and lavender to soothe and restore the skin's natural balance.
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"When you are more active and in a warmer environment, you tend to produce more oil and perspiration, which can lead to clogging, spots and cloudy-looking skin," explains White. "Make sure you are using a cleanser that cleanses gently yet thoroughly, and that removes all traces of make-up, dirt and oil. Use a moisturiser or treatment with salicylic acid in it to keep pores clean and clear."
Beware of going overboard and trying to strip all the oil from your face, as your skin will simply produce more to compensate.
The Yes To Tomatoes range contains lycopene to absorb surface grease, as well as helping balance oil production. Try the Trouble-Free Facial Wash, £8.99. The Simple Clear Skin Oil Balancing Exfoliating Wash, £3.99, contains witch hazel which is great for particularly sensitive skin, and Nuxe Eau Demaquillante Micellaire Aux 3 Roses, £15, contains flower and green tea extract to gently get rid of impurities.
Tackle any breakouts with an intensive spot treatment. Try Dr Nick Lowe Spot Treatment Gel, £8.95, or Beautycycle Fire Restoring Balance Anti-spot gel, £8.40, as both contain salicylic acid.
A mattifying lotion will also help limit a shiny forehead during the day. Dermalogica Oil Control Lotion, £26.40, regulates the amount of sebum your skin produces – use it under your normal moisturiser – while Matis Reponse Purete Intensive Purity Serum, £42, contains AHAs to gently exfoliate and extract of Enanthia Chlorantha, an African tree, to cut oil production.
Another option is Champneys Purify & Balance Moisture Lotion, £15, which uses silica to keep the skin matte and iris extract to prevent further breakouts.
Once a week, use a clay or deep-cleansing mask to intensively treat your skin, such as Elemis Herbal Lavender Repair Mask, £26, with antiseptic rosemary, thyme and lavender essential oils.
"To reverse the signs of sun damage, you need to incorporate a few key ingredients into your daily and weekly skincare routine. Make sure you are using a retinoid. An over the counter retinoid, or retinol, helps diminish the appearance of uneven pigmentation. Using topical vitamin C will also help - mix a scoop of Philosophy Turbo Booster C Powder, £28, into your favourite serum or moisturiser daily."
Penford also recommends looking for ingredients acting as melanin suppressors, to tackle the pigment that colours the skin. "Newer ingredients such as zinc glycinate help control melanin activity, while many botanical extracts also inhibit melanin production. These include kiwi fruit, mulberry, bearberry, liquorice and giant fennel."
Clinique's Even Better range boasts prescription-strength results over the counter. The brand new Clinical Dark Spot Corrector, £37.50, uses plant-derived technology to brighten the skin, while Skin Tone Correcting Moisturizer SPF 20, £32, reduces the appearance of excess pigment and stops spots surfacing.
Dermalogica's ChromaWhite TRx collection, from £33.20, includes cleanser, a powerful exfoliant and two skin treatments, as well as a day and night cream.
You can give your usual skincare regime a boost with SkinCeuticals Phyto Corrective Gel, £25, containing natural plant-based skin lighteners, under your daily moisturiser. For a more intensive treatment, Perricone MD Pigment Corrective, £75, uses pycnogenol to improve tone plus vitamin C ester to brighten.
Even if you don't suffer with sensitive skin the rest of the year, the heat can trigger reactions, with nearly two thirds of those affected saying it reduces their confidence, according to a survey by sun cream producers Piz Buin.
"Prickly heat occurs when your body is sweating at a greater rate than normal and sweat becomes blocked in the skin, creating blister-like pimples," explains Penford. "This may be caused by build-up of dead cells on the skin or heavy clogging skin products. Avoid ingredients such as mineral oil, lanolin and heavy waxes, and exfoliate regularly."
Skin Shop Kalme Undercoat, £17, works as an 'armour' for sensitive skin, creating a barrier to help reduce the nerve response and prevent your skin reacting.
Superdrug has recently launched its own gentle, hypoallergenic Simply Pure range, all at £2.49. Ingredients include soothing allantoin and calming Soothex. You can also try Artistry Essentials Soothing Creme, £15.27, packed with black bamboo, liquorice and blue lotus to calm stressed skin, or Avene Skin Recovery Cream, £12, made from 67% Avene thermal spring eater, known for its soothing properties.
To tackle flushed or red skin, Dr Nick Lowe Redness Relief Correcting Cream, £14.63, is lightly tinted, plus it contains cooling menthol, arnica, chamomile and allantoin to soothe, while Boots No7 Calm Skin Redness-Relief Gel, £17.50, does exactly what it says on the tube.
Whenever you need an extra boost, Organic Surge First Class Mask, £6.99 from Boots, has skin-calming chamomile and soothing marshmallow to treat sensitive skin in five minutes, while Dr Andrew Weil for Origins Mega-Mushroom Skin-Calming Face Mask, £30, uses black bamboo leaf extract, and natural ingredients to tackle redness and repair the skin's natural barrier.