Five common mistakes when using sunscreen that could cause sunburn

Sunburns become one of the main visits to health centers every summer. You only have to walk around any Spanish beach (or swimming pool) to see that, despite the ever-increasing information about the risks of sunburn, many people still have sunburned areas on their bodies. Skin cancer is the type that has increased the most in Spain, with a 40% increase in recent years, according to the Spanish Association of Dermatology and Venereology (AEDV), and the culprit is none other than the sun, which is so sought after during these months.

The main mistake is thinking that a healthy tan is possible. "From a pharmaceutical perspective, there is no such thing as a safe or healthy tan. A tan is a sign that the DNA in our cells has already suffered an attack. The damage is cumulative and not always visible in the short term, but it becomes visible over time," explains Karla Pires , pharmacist and quality manager at Planet Skin.

Since a healthy tan doesn't exist, the key is to avoid sun exposure in order to achieve a tan. This isn't something many people are willing to give up, so the alternative is to protect yourself properly with sunscreen . But again, it's not enough to simply apply sunscreen and forget about it, because there are certain fairly common mistakes that could cause skin burns.

One of the most common mistakes with sunscreens is using too little, which can cause burns. As pharmacist Gema Herrerías explains in her book "The Definitive Guide to Skin Care": "Sunscreen is effective if used correctly. Common occurrences such as applying too little, forgetting to cover certain areas, not reapplying during sun exposure, or excessive sweating can significantly reduce its protective capacity." And what is the necessary amount, you might ask? According to the expert, sunscreen filters are calculated "after applying 2 mg/cm² of sunscreen to the skin every two hours , corresponding to one teaspoon to cover the face or six teaspoons to cover the entire body surface of an average-sized person."

On the other hand, experts advise reapplying the cream at least every two hours , and always after bathing, even if you use a waterproof product.

According to many experts, the best sunscreen is the one you use, so it's important to choose a texture and format that suit your tastes and needs. However, it's essential that the product you choose be broad-spectrum, meaning it protects against UVB rays, indicated by SPF, UVA rays, blue light, and infrared rays . Although UVB rays cause sunburns and DNA damage in the skin, UVA rays also play an important role in skin cancer, in addition to photoaging and pigmentation. All of this must be indicated on the packaging. Regarding UVB rays, Zuberoa Carreras , a nurse, dermoesthetics expert, and Faro EdTech collaborator, points out that "the SPF (Sun Protection Factor) should be at least 30 for daily use, and ideally 50+ for prolonged outdoor activities."

Another mistake is applying sunscreen to wet skin, something common when you're at the beach or pool. "If we apply sunscreen to wet skin, its effectiveness is reduced by almost half . That's why it's important to dry thoroughly with a towel before reapplying. If you use SPF 30, you'd only be protecting yourself with SPF 15 on wet skin," warns Karla Pires.

Sunscreen, when properly chosen and applied, is a good shield against the sun, but it's best to combine it with other forms of protection to avoid burns. " Sunglasses, a hat, light but thick clothing ... Everything helps. Furthermore, including foods rich in antioxidants—such as tomatoes, watermelon, red peppers, or berries—in your diet helps neutralize the oxidative stress generated by the sun," recommends pharmacist Karla Pires. And if you want an extra boost, sun nutricosmetics are an option: " Oral supplements with carotenoids, vitamins C, or E can prepare the skin for summer and strengthen its natural defenses, although they should never replace topical sunscreen," she adds.

Finally, another common mistake is not applying sunscreen to certain areas of the body that end up reddened and even burnt: the shoulders and back, hands, insteps , armpits, nose, ears , lips, eyelids , and, in the case of men with baldness or very fine hair, the scalp. These are areas that are often forgotten when it comes to protecting them and can also suffer the negative consequences of prolonged sun exposure.