How UV rays cause sunburn - and why sun cream still matters in spring

The sun in spring has the same strength as it does in late summer, so if you’re waiting to feel hot before you reach for the SPF, you’re sure to end up red-faced.

Here’s everything you need to know to keep yourselves and your loved ones safe.

What actually is UV?

“UV” refers to ultraviolet radiation – a form of electromagnetic energy naturally emitted by the sun that can penetrate the skin and cause effects like burning and long-term skin damage.

UV radiation is also produced by artificial sources like tanning beds and certain lamps.

There are several types of UV, but those most linked to skin cancer are UVA, which penetrates deep into the skin – linked to wrinkles and ageing and long-term damage – and UVB which affects the surface of the skin causing sunburn and plays a key role in skin cancer.

Why is it dangerous to get sunburnt?

In the short term, sunburn is an inflammatory injury.

UV radiation damages skin cell DNA, and your immune system responds with redness, heat, swelling and pain.

In more severe cases, you can get blistering, fever, chills, or dehydration – it’s essentially a mild radiation injury.

The bigger concern is what repeated or severe sunburns do over time.

Each burn increases cumulative DNA damage in skin cells.

Your body can repair some of it, but not always perfectly and that raises the risk of skin cancer – one of the UK’s most common cancers and also one of the most preventable.

Can sunshine be beneficial?

Yes, it is good for us, but the key here is controlled moderation.

Sunshine is key to the healthy functioning of the body through the production of vitamin D for bone health, immune function and muscle strength, serotonin to boost mood and mental health and reduce seasonal depression – and even sleep regulation by helping to set your circadian rhythm, making it easier to sleep at night and feel alert during the day.

Using suncream allows you to gain these benefits safely.

Can I get sunburnt when it’s cold?

This is where a lot of people get caught out.

The risk of sunburn has nothing to do with temperature and everything to do with the strength of the sun.

Skiers wear sunblock on the slopes when temperatures are well below freezing – and many of us have been caught out on a bright day with a cold wind that made it feel quite chilly.

This will be particularly true towards the east coast over the next few days; a cold east to northeasterly wind will make it feel cold enough for coats but the strength of the sun – and therefore the risk of burning – will be just as great in the east as it is across more sheltered western areas where temperatures rise to 21C.

The sun in spring has the same strength as it does in late summer. / Credit: PA

Will suncream stop me from getting a tan?

No, it just happens more slowly and usually more safely as you’re much less likely to burn, which is the real damage you want to avoid.

What do the experts say?

In his many years of practice, Mr Gurjinderpal Singh Pahal, Consultant Plastic & Reconstructive Surgeon and Lead Clinician at The Royal London Hospital, said most of the melanomas he saw and removed were “entirely preventable”.

“The sun accumulates its damage silently, year after year, deep in the DNA of your skin cells, long before anything is visible to the naked eye.

“Ultraviolet radiation is, without question, the most pervasive and underestimated carcinogen in our daily lives. None of my patients, looking back, have ever wished they’d worn less sunscreen.

“My advice is unequivocal — broad-spectrum SPF 50, every morning, every season, regardless of cloud cover. The tan fades in a fortnight; the damage, I’m afraid, is rather more permanent. The bottom line is that the skin remembers everything, and you should do whatever you can to protect it”