The days of people using baby oil to ‘tan’ their skin are, thankfully, long gone. But from what I see as a consultant dermatologist (in the NHS and private practice), many people are still not applying enough protective, high-factor sunscreen on holiday abroad – or in the UK.

On a recent holiday in Cornwall, looking out on to the beach, it was amazing – if alarming – to see how many people had moderate to severe sunburn by 4pm.

The need to use sun protection here at home might surprise you, but this is true even if you’re someone who doesn’t burn easily or has darker skin.

The lovely warmer weather of this Bank Holiday weekend means lots of people will have been out enjoying the sun without appreciating the risks from the UV radiation – sadly, I’ve treated patients for skin cancer, including malignant melanoma, who have rarely travelled abroad for a holiday or who’ve never left the country.

The World Health Organisation categorises excessive exposure to UV radiation as a Group 1 human carcinogen – the same classification given to asbestos and tobacco.

This is borne out by the tragic fact that seven people die from malignant melanoma every day in the UK.

And cases are rising, with a record-high number reported last week by Cancer Research UK. Yet skin cancer is largely preventable.

The clearest sign of sun damage is sunburn, which in turn raises your risk of skin cancer – the more you get sunburnt (especially in childhood), the greater your chances are of developing it.

Each additional blistering sunburn before the age of 15 increases the relative risk of melanoma by 3.2 per cent, according to a major study of over 44,000 participants published last year in the Journal of the American Academy of Dermatology.

But it’s not just sunburn that raises your risk of sun damage and cancer – we know that long-term sun exposure does, too.

And whatever is being said on social media by influencers, you really cannot ‘train your skin’ to build protection against sun damage by slowly tanning.

It’s true that skin builds up a degree of tolerance to the sun, as light triggers cells in our skin to release melanin, the dark pigment that causes a tan.

This is the skin’s attempt to protect itself, as melanin absorbs more of the UV radiation that damages skin. But while skin that’s exposed to more sunlight may not burn so easily, chronic sun exposure will still cause damage over time. A tan is a warning sign that the skin is already damaged.

The idea that a pre-holiday sunbed will protect against sun damage is also rubbish – the levels of UVA, the type of ultraviolet radiation used in sunbeds, are up to ten times the sun’s and each use under the age of 35 increases the risk of melanoma by 75 per cent, reported the Journal of the European Academy of Dermatology and Venereology last year.

Sunscreen is vital. And not ‘just’ to prevent skin cancer. Around 80 per cent of visible ageing is to do with external factors such as UV light and pollution.

I have worn sunscreen every day since I was 23, even before I started training to become a dermatologist.

At the age of 54, I’m told I look younger than my years – and I think this is largely to do with protecting my skin from UV.

While there are very good treatments available for signs of sun-related premature ageing, such as dark sunspots, thread veins and rough or scaly patches (treatments such as targeted prescription creams, peels and laser, which I use in clinic), prevention is more effective – and certainly much easier and cheaper – than cure.

Young women in their 30s and even their 20s often come to my clinic asking for Botox and other anti-ageing treatments. But in my view, not only are these treatments unnecessary for them, but there is also one much more effective and cheaper preventive: Wearing SPF50 – particularly in the spring and summer. This applies to men, too.

Skin conditions such as rosacea are also affected by UV exposure.

That might surprise many, but studies suggest sun exposure is the top trigger in more than 80 per cent of sufferers (rosacea causes an angry rash, a red, inflamed nose and spots). Even a walk on a sunny day in winter is a big trigger for some, which is why I particularly stress to my patients with rosacea the importance of using sunscreen on their face – for some, that means all year around.

But, of course, what’s important is applying enough sunscreen to get the sun protection factor (SPF) promised on the label and to make sure it has broad spectrum cover for UVA and UVB wavelengths. To get the true SPF, you need to apply 2mg of cream per square centimetre of skin – this is how it’s applied in lab tests. Yet research shows, on average, we apply less than half of this.

Use my guide to work out how much protection you actually need:

As A general rule, you need at least six teaspoons of cream to cover the body. For a week’s holiday, you should pack at least a 200ml bottle per person.

Choose a product that protects against both UVA and UVB (the main cause of sunburn) – both wavelengths are associated with ageing and DNA damage, which can lead to skin cancers.

The SPF on the label shows the UVB protection, i.e. how much more UVB radiation your skin can absorb before burning compared to unprotected skin.

UVA rays penetrate deeper into the skin – protection is measured in stars, choose at least four (or ideally five) star protection.

Whether in the UK or abroad, I would recommend always wearing an SPF50 – and in the UK apply it to all exposed skin once the UV index is above three.

In the UK, this is usually from April to September/October – but beware of warm days in March when winter skin will be more vulnerable to sunburn, as it will have built up less melanin.

As per new Australian guidelines, this should be adjusted for darker skin tones to allow for some sun exposure as there is a risk of not getting enough vitamin D – but sunscreen is still needed for extended periods in the sun. I apply SPF50 to the face, neck and hands all year round, mostly to protect against myself against UVA and visible light in winter.

Don’t assume that a moisturiser that has an SPF is enough protection – swap your face cream with SPF for a proper sunscreen, at least in the summer.

Not least as while a face cream might have SPF, it doesn’t always offer protection against UVA too. While it’s really important to protect your skin at home, the most dangerous pattern of sun exposure is if your skin has been covered for most weeks of the year and then is suddenly exposed to high UV levels on a two-week holiday, with subsequent sunburn.

This pattern is linked to the development of melanomas.

Even really good, well-applied sunscreen is no substitute for covering up and staying in the shade – but you will still need sunscreen, as the UV rays can bounce off surfaces, such as water, sand and even grass.

And finally, try to apply sunscreen before you go out, because this allows for even coverage and film formation for maximum protection.

Your face needs...

Nose, ears and hairline: A 5p blob for each area

I always recommend applying two layers to the face a few minutes apart to prevent gaps in application.

Nose: This is a very common area for skin cancers as it protrudes from the body, so is more vulnerable as it gets more direct sunlight (it’s the same with the shoulders and the tops of the feet). It’s important to protect it – not least as surgical treatment of skin cancers on the nose can be quite disfiguring as there isn’t much skin to play with here.

You need to apply SPF more regularly – around two-hourly – as we sweat quite a lot in the centre of the face, and the skin there tends to be oilier, as there are more sebaceous (oil-producing) glands – we also tend to rub our nose, so sun cream will rub off a bit more.

That’s why for the nose I recommend a two-pronged approach – a standard chemical sunscreen (common ingredients in these include octocrylene and avobenzone) – plus a decent application of zinc oxide paste. As for amounts, you want the skin to be visibly white, which suggests adequate cover. If you’re doing water sports, think white nose and ears!

Ears: This is a common site for skin cancers, especially in older men – probably because men are more reluctant to use sun cream and they’re also more likely to have short hair or a bald scalp where there is no protection from hair. Skin cancer here is often at higher risk of spreading. Cover the tops of the ears, the lobes and also inside the rim of the ear. Many people miss this last one.

Hairline: Few people put sun cream in their parting – hair is very good at shielding you from sun damage. We know this because men who have had beards for a long time and then shave them off often have notably less sun damage where their beard was. But a parting is very vulnerable.

I personally don’t wear sun cream in my parting, I wear a hat, but I know there are some very good sprays now available that are less greasy.

Rest of face: Two 10p blobs for each side

The tops of the cheekbones, just below the eyes, are common areas for sun damage and skin cancers – people tend to miss these areas because they don’t like to get sun cream too close to their eyes as they find it irritating. So as with the hairline, use a mineral sun cream like zinc oxide around your eyes, as this tends to be less irritating. This is what I do. And wear sunglasses. 

Forehead and back of neck: A 10p blob for each area

Forehead : Skin cancer is also common here, but I find some people are reluctant to use sunscreen in the upper part of their forehead – especially if they play sport – as it runs when they sweat and irritates their eyes. To get around this, try a zinc oxide sunscreen or cream stick as this tends not to run as much, and mineral suncreams tend to be less irritating. (There are also clear zinc products which have a lighter texture and are less white, but usually not quite as effective.)

Back of neck: Again, a classic place to burn, especially for those with short hair. But don’t skip it if you have long hair as you might tie it up during the day if it’s hot, or if you’ve been on the beach – the back of your neck will be especially vulnerable, as it won’t have been exposed for most of the year.

Your body needs...

Shoulders: Two 10p blobs

Like the back, this is an area that’s often missed and it is also vulnerable because, as with your back, legs and stomach, your shoulders are covered up for much of the year.

Your lower arms, hands and face will have had sun exposure even in winter, but the same isn’t true of your shoulders if you take off your cardigan on a hot day.

Chest: One 50p blob 

A lot of women who have protected their face from the sun don’t do the same for their neck and chest; sun damage really shows up in this area, with dark sun spots and paler patches that have lost their pigmentation, thread veins and texture changes – as well as damaging blood vessels and cells that control pigment, the sun triggers enzymes to break down collagen.

As a result, the skin on the chest often becomes crepey and quite rough to touch.

Stomach: One 10p blob

Another area, like the back, that’s vulnerable to the sun, as it doesn’t normally see the light of day – in my view, though, particularly at the beginning of a holiday, it is probably better to cover up this area frequently or stay in the shade. 

Scalp: One 50p blob

I see a lot of sun damage and skin cancer on scalps of men who have lost their hair, so you must use sunscreen here, too. Better still, wear a hat. A baseball cap is fine but something with a full brim like a Panama hat is even better as it shades the ears and face. 

Back: Two 50p blobs

When the sun comes out, many men are quick to take off their tops, and the back is the most common area of the body where we see melanoma in men (in women, it’s their legs).

I take a lot of skin cancer off backs, even though it’s not a particularly sun-exposed area for most of the year – it is therefore critical that men apply high factor sun cream to this area.

Arms and legs: Two 10p blobs for each limb

Arms: Another area people don’t worry about, especially the lower arms, as the skin here tends not to burn as easily because it gets more exposure to sunlight throughout the year. But arms still need protecting and this is one of the earliest areas to show sun ageing.

Legs: This is the most common site for melanoma in women. The backs of the thighs in particular are prone to burning, as not only are they harder to put sun cream on yourself, but they’re covered up for much of the year. I treat a lot of people in their 40s wanting to get rid of sunspots on their lower legs.

Dr Justine Hextall is a consultant dermatologist at Tarrant Street Clinic in Arundel, West Sussex

Additional reporting: Jennie Agg