If you’re going to be spending a lot of time in direct sunlight, then it’s always best to go for SPF 50, even if you want a tan, and especially if you’re having a beach or pool day. Trust us, you’ll still get a tan, but your skin will be much better protected from those harmful rays. You’ll need to reapply your body sunscreen every two hours or every time you get wet. SPF 50 only offers slightly higher UV protection (around 2%), but over a lifetime, this does make a very big difference. As for temperature, our study shows a rise in temperature after the use of sunscreens, with an average increase of 0.76 °C on the face and 0.68 °C on the forearm. These results are contrary to those obtained by Ou-Yang et al. in their study regarding the impact of sunscreens on the skin during exercise, as they did not observe any change [ 8]. However, it is important to highlight the fact that the method used to obtain the measurements was different for the two studies. Ou-Yang took the first temperature immediately after applying the sunscreen to people doing physical exercise [ 8], and we evaluated changes after 20 min in resting conditions, without including physical exercise. Despite discrepancies, the increase in temperature experienced in our study is not significant, and remains within the normal parameters of skin temperature established by Benedict et al. In their work, they determine a normal range between 31 and 35 °C of temperature, depending on the body zone, with a higher temperature in the facial zone and lower in more distal zones such as the forearm [ 9, 10]. This distribution is also present in our data, in which we observe that the facial temperature is higher than the one obtained on the forearm and that both are within the normal range. Water-resistance to stand up against sweaty days or time spent swimming. Heads up: There’s no such thing as water proof or sweat proof sunscreen. Under current FDA guidelines, there are only “water-resistant for 40 minutes” or “water-resistant for 80 minutes” options. "Sweat- and water-resistant" labeling means the formula maintained its SPF level on testers’ skin in a water bath for the indicated time, says Steven Q. Wang, M.D., a board-certified dermatologist at Memorial Sloan Kettering Cancer Center in Basking Ridge, New Jersey. Beyond that timeframe, it should be reapplied. It is known that solar radiation has both harmful and beneficial effects on humans, for example, ultraviolet B radiation produces erythema and DNA damage; simultaneously, it induces the synthesis of previtamin D3. In addition to UVB rays, it has been shown that UVA1 rays also induce erythema, a very important factor in the pathogenesis of melanoma and other skin tumors such as keratinocytic carcinoma [ 4]. However, UVA rays also contribute to blood-pressure control and cardioprotection by inducing nitric oxide release from photosensitive derivatives of intracutaneous nitric oxide.

While sunscreen is often the first thing people reach for in terms of protection, remember that covering your skin is even more effective. Protective clothing, like sun hats or UPF clothing, are another tool to keep in your sun safety arsenal. Sunscreen should be reapplied every two hours, but be extra careful during peak sun times — 10 A.M. to 4 P.M. — depending on the season of the year.The sneaky thing about sun damage is that it accumulates over time, and we may not even notice that our skin has sustained small amounts of damage until it's too late," says Dr. Engelman. "Protecting your skin everyday with sunscreen should be an automatic part of everyone's routine." Skin pH is another essential parameter for the evaluation of epidermal functions, as the acidic nature of pH influences skin-barrier function, lipid synthesis and aggregation, epidermal differentiation, desquamation, skin-barrier regeneration and skin antimicrobial-response [ 14, 15]. Elevated pH values are related to the loss of antimicrobial activity, and it has also been shown that, in patients with atopic dermatitis, higher values of the SCORAD index are associated with skin-barrier dysfunction, which is reflected in higher pH and temperature and lower SCH and elasticity [ 15]. In our study we observed that despite the increase in pH after the application of the sunscreen, the values remain within normal ranges, and therefore the epidermal barrier is not affected by it. In many cases yes, but for daily protection, face-specific sunscreens have a slightly lighter formulation that your face will thank you for. Some skin types will find that their face responds just fine to body sunscreen, but for oily and breakout-complexions, it’s definitely best to use a sunscreen specifically formulated for the face. Chemical formulas absorb UV rays and convert them into heat, according to Michael Somenek, M.D., a plastic surgeon in Washington, D.C. "This process allows the body to release the UV rays, which ultimately prevents the skin from burning," he says. Chemical sunscreens tend to be better for swimming due to their water-resistant nature but while these lotions and sprays are easier to apply with no white residue, you will need to reapply sunscreen more often than you would with a physical or mineral option. ORIGINAL SPF 30 SUNSCREEN LOTION. This is the stuff we use every day. It’s the formula that started it all. People say it smells like summer. We like that. Whether we’re spending a lazy day at the beach or just hangin’ out, our Original formula is definitely our fav.

With the help of Cult Concierge skin care expert { Ryan}, we’ve answered some of the most important questions about SPF and rounded up the very best body SPFs for all skin types. What SPF should body sunscreen be? Let's get one thing straight: You should be wearing sunscreen everyday, rain or shine. Protecting your skin from the sun is essential — no matter your skin tone, location, or the forecast. Wearing sunscreen is our number one defense against skin cancer and comes with a variety of skin benefits, too. Want to protect the skin barrier? Sunscreen can do that, no problem. How about limit acne scarring? Yup, sunscreen can aid with that, too. And as for reducing fine lines, sunscreen has you covered there as well. Trust us, there's really no reason to ever skip it.The formula is only water-resistant for up to 40 minutes, so you need to remember to reapply if you're swimming or sweating. The variations between the sunscreens could be due to differences in their composition but also to the differences between the two anatomical regions. It has been shown that the skin of the face is thinner than that of the rest of the body, and that its stratum corneum has fewer layers of corneocytes [ 10, 25], so the effect that the different components have could be greater at this level. In addition, several studies have shown that water-based emollients increase TEWL in psoriasis patients [ 6], which could explain our increase in facial TEWL, as they are water-based sunscreens.