For many of us, summer is synonymous with escaping to the high alpine, hot days at the lake, or weekends at the beach. These kind of activities also tend to be accompanied by a lot of sun exposure, which means there’s plenty of potential for sunburns. Everyone is at the mercy of the sun, especially in the summer and even more so at high altitudes or with the reflection of water. Getting sunburnt sucks, but thankfully it can be avoided with just a little bit of preparation and diligence.

The main concerns with not ‘screening up are the short term effects of ultraviolet (UV) radiation found in sunburn and the long-term predisposition for skin cancer—the most common type of cancer in the United States, according to the American Cancer Association. UV radiation comes in multiple forms: UVA, UVB, and UVC. We are primarily concerned with UVA, which is about 95% of the UV radiation coming from the sun and can penetrate our skin as deep as the dermis. UVB on the other hand is less abundant but higher in energy, with the ability to penetrate to the epidermis. Together, these two forms of radiation damage our skin cells on numerous levels. However, we can protect ourselves using sunscreen, sun protective clothing, hats, and sunglasses.

Sunscreen

Sunscreen is rated by its Sun Protection Factor, or SPF. The SPF quantifies the amount of protection a product provides against solar energy. It is a measure of how much solar energy (UVB radiation) is required to produce sunburn on protected skin (i.e., with sunscreen) compared to unprotected skin. While SPF typically measures only UVB, a broad spectrum sunscreen means that it was tested for UVA and UVB.

The SPF does not tell you the time that you can stay in the sun, because the solar energy varies and is influenced by a number of factors. Solar energy changes with the time of day, (midday having the greatest), geographical location (closer to the equator is stronger), and cloud cover (less cover allows stronger energy through). Solar energy exposure is also influenced by skin type, the quantity of sunscreen applied and the frequency of application. So, protecting yourself with a SPF15 sunscreen means that your exposure can be 15 times longer with that sunscreen than without.

We typically recommend using a minimum SPF of 15 and applying it 15 minutes before going into the sun. If you are on a trip, apply as part of the morning routine like brushing your teeth. That way, no matter what the activity is, as you get ready to leave, sunscreen isn’t lost in the hustle and bustle of getting on the snow or water. It seems to take a yearly reminder to cover the “unusual” spots (tops of feet, tips of ears, balding areas, lips) so we are reminding you now to help ensure you don’t forget this year.

Physical vs. Chemical Sunscreen

There are classically two types of sunscreen: physical and chemical. Physical sunscreen is often also called mineral sunscreen, because it’s made from zinc oxide and/or titanium dioxide. The main difference between these two types of sunscreen is how they work. Physical sunscreen sits on top of your skin, forming a reflective layer of minerals, whereas chemical sunscreen is absorbed into your skin, where it deactivates the UV light. Both are safe and effective, but do have different benefits and drawbacks.

Mineral sunscreens are effective as soon as they are applied, generally easier on sensitive skin, and can protect against both UVB and UVA rays. However, they can result in a whitish hue on the skin and aren’t as easy to apply evenly. These tend to come in either a tube of thick-ish lotion or as paste in a can or stick. Due to their thick nature, mineral sunscreens are great for water activities like swimming or surfing.

Chemical sunscreen on the other hand can take time to be absorbed by the skin, as it’s most often applied as a cream or spray. This is why they almost always recommend applying before you go in the water or begin sweating heavily. One downside to chemical sunscreens is that they can wear off sooner, and therefore must be reapplied more often. In the end, both physical and chemical sunscreens are effective when used according to their directions, so it’s quite often a situation of whatever you find works best for you.

Application

All sunscreens must provide directions on when to reapply, however, reapplying every two hours and after exposure to water is generally recommended. No sunscreens are "waterproof” and all eventually wash off. Sunscreens labeled "water resistant" are required to be tested according to the required SPF test procedure and the labels are required to state whether the sunscreen remains effective for 40 minutes or 80 minutes when swimming or sweating. And per usual, nothing lasts forever—sunscreen expires after three years, unless labeled sooner.

If you are swimming or diving, is your sunscreen “reef safe”? Recommendations from professionals in the areas greatest affected by coral die-off say not to use sunscreen at all and cover with UPF rated clothing instead. However, recommendations for reef safe sunscreens say to use those that create a physical barrier not a chemical one. Look for the active ingredients zinc oxide and titanium dioxide (non-nano in size), and use a stick form because aerosolized titanium dioxide can be harmful if breathed in.

Clothing

Clothing is rated by the Ultraviolet Protection Factor (UPF), which measures the UV light transmitted to skin. For reference, a cotton t-shirt is rated UPF 5.

UPF 50 blocks 98% of UV light from reaching the skin
UPF 30 blocks 96.67% of UV light from reaching the skin
UPF 15 blocks 93.33% of UV light from reaching the skin
<UPF 15 is not considered UV protection

The lifespan of UPF clothing is 2-3 years or less depending on wear. Some considerations are that darker fabrics usually provide more UV protection than lighter ones, and denser weaves provide more UV protection than looser weaves. Polyester and nylon also offer more sun protection than natural fibers. If you are diving, swimming, or surfing, we definitely recommend you consider UPF-rated clothing.

Hats

For the most protection, the ideal hat has a full brim covering your face, ears, and neck. Tightly woven fabrics offer more protection than those with holes allowing sunlight to penetrate. A consideration if you are using a baseball cap, is to wear a buff that covers the neck and can be pulled up over your ears.

Sunglasses

Sunglasses prevent damage to the eye’s surface tissue, including the cornea and lens. Pinguecula is a protein and fat deposit in the sclera (white part) that interferes with tearing. Pterygium (surfer’s eye) is a growth extending from the sclera to the cornea and can cover the iris and pupil. Long term damage can lead to cataracts and macular degeneration. Again, we are concerned with UVA and, especially UVB protection.

When purchasing glasses, look for 100% UV protection. This might be labeled differently such as UV400 or “UV absorption up to 400 nm.” Polarized glasses are designed to block horizontal light thus protecting from the reflected light from snow or water. However, the increased glare protection does not mean there is more UV protection. A wilderness consideration is that polarized sunglasses can impair visibility of ice patches when skiing, boarding or driving. Another thing to evaluate is whether UV light is blocked from the sides by oversized lenses, wraparound frames, or side shields.

Darker does not mean better. Neither does price or lens color. We said that nothing lasts forever and this is a case where research is inconclusive. You can have your sunglasses tested at an optical shop that has a UV light meter.