Healthcare 101: A Complete Guide to Sunscreen

Modified February 25, 2026

Summertime means fun in the sun, from picnics and outdoor sports to lounging on the beach and in backyard pools. To safely partake of all these great outdoor activities, it’s essential to protect yourself from overexposure to the sun. Skin cancer is the most common form of cancer in America: The EPA estimates that “90 percent of non-melanoma skin cancers and 65 percent of melanoma skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun.” That means preventative measures should be taken when dealing with the sun. You may have heard many theories about how to do that — including the idea of clouds acting as your sunscreen. Let’s explore that and other ideas you may have overheard about sun protection.

Sunscreen and UV Rays

The purpose of sunscreen is to limit the amount of ultraviolet (UV) radiation that penetrates the skin. There are two major types of UV radiation that affect your health: UVA and UVB. These forms of ultraviolet radiation cause premature skin aging, damage to the skin and elevated risk of skin cancer. What’s the difference between these two types of UV radiation? UVA light penetrates the skin deeply and leads to sagging and wrinkling. UVB rays, on the other hand, are associated with sunburn.

It’s important to note that both types of ultraviolet light can increase your skin cancer risk, which makes it important to find a sunscreen that blocks them from penetrating the skin. When used properly, sunscreen forms a layer on the skin which protects it from ultraviolet light penetration.

Common Sunscreen Myths and Misconceptions

“Clouds Are My Sunscreen” – talk about malarkey! As you’ve probably heard from your mother or lifeguard (who were correct — and rightly concerned for your health), you can indeed still get sunburned on cloudy or partly cloudy days. 80% of the sun’s UV rays still penetrate clouds.

Other common misconceptions

“Tanning Beds Are a Safer Alternative” – Despite what you might be told about “controlled doses” of UV radiation, tanning salons typically administer heavy doses of focused UV radiation. You’re exposing yourself to high levels of UVA rays which prematurely age your skin. According to SkinCancer.org: “Indoor tanners are 74% more likely to develop melanoma, than those who have never tanned indoors.” Wearing sunscreen in tanning beds does not make them any safer.

“A Base Tan will Help Prevent Sunburn” – Scientists have largely debunked the idea that there is any benefit behind getting a preemptive “base tan” via tanning bed or the sun. You can’t change your skin type by increased exposure (if you’re pale or fair, that’s not going to change). Any change in skin color you experience through tanning is technically skin damage, so exposing yourself to additional UV radiation before a cruise, beach trip, etc. only increases your chances of long-term health risks.

“Dangerous Chemicals in Sunscreen are Worse Than Sun Exposure” – Sunscreens are for the most part safe to use and effective when used properly. The chemicals in sunscreens are all FDA approved. If you have skin allergies, read labels carefully and avoid lotions that contain alcohol, fragrances and preservatives that might cause irritation. If you’re concerned about certain chemicals as a consumer, you can avoid products with avobenzone and oxybenzone.

What Is SPF?

The most important number on a bottle of sunscreen is the SPF, or sun protection factor. Many people misunderstand the meaning of this number. SPF refers to the ability of sunscreen to protect you against UVB rays. It is important to know that this scale is not linear. Thus, a SPF of 30 is not twice as effective as an SPF of 15. Info on various SPF levels:

• SPF 15 blocks 93% of ultraviolet rays
• SPF 30 blocks 97% of UV rays
• SPF 50 blocks 98% of UV rays

No sunscreen can block 100% of the ultraviolet light from the sun. Although higher SPF yields greater protection against UV light, the returns are incremental. Wearing an SPF 30 sunscreen is appropriate for most people, although you may want a higher SPF sunblock for your face.

Mineral vs. Chemical Sunscreens

There are two kinds of sunscreen on the market today: chemical and mineral. Chemical sunscreens work by producing a reaction on your skin that blocks UV rays, while mineral sunscreens are “physical blockers” that scatter and deflect the sun’s rays.

One compound found in chemical sunscreens called 4-MBC is considered a possible “endocrine disruptor,” or hormone disruptor. Hormone disruption impacts any biological processes that rely on hormones, like pregnancies and birth outcomes. Hormone disruption can lead to developmental issues, birth defects and even tumors.

Though more research needs to be done, there is evidence that oxybenzone can also lead to allergic skin reactions in some people. But today, chemical sunscreens are still approved by the FDA; and that means more research is needed to solidify a proven link.

If you’re concerned about the ingredients in chemical sunscreen, a mineral sunscreen might be an option for you. The tiny particles of titanium dioxide or zinc in mineral sunscreens physically scatter UV rays, as opposed to causing a chemical reaction to block them.

Other ingredients to look out for in chemical sunscreen include octinoxate — whose chemical effects on estrogen have the potential to be harmful for humans and wildlife — and homosalate, which accumulates in the body faster than we can expel it and may become toxic. Paying attention to both active and inactive ingredients in your sunscreen choice can help you research the best product for your lifestyle.

How to Apply Sunscreen

The most common mistake people make when applying sunscreen is failing to apply enough. Putting on a very thin or inconsistent amount of sunscreen can leave your skin vulnerable to burning and the increased risk for skin cancer. To ensure you get the full benefit, apply 1 ounce of sunscreen to your body. Apply the sunscreen at least 30 minutes before you intend to go out into the sun to ensure that it binds to your skin to protect you.

Follow the directions on your sunscreen bottle to reapply. In general, it is best to reapply sunscreen every two hours. Make sure you apply more after swimming, toweling off or sweating profusely, as these activities can remove your protective layer of sunscreen. Certain formulations of sunscreen are labeled “sweat resistant” or “water resistant.” These tend to be slightly stickier, but they are a good choice when you are anticipating a hot or sweaty day. Also make sure that you wear sunscreen on cloudy days, as UV light easily penetrates the clouds. Wear your sunscreen and enjoy this beautiful summertime sun. If you do get burnt and need medical help, contact CareSpot. We treat burns, rashes and many other ailments.

Additional Ways to Protect Yourself

• Always wear SPF of 30 or higher when outdoors.
• Try to avoid direct sunlight between the hours of 10 a.m. and 2 p.m. when the sun is at its hottest
• Wear extra protection such as long sleeves when in the sand, water and snow as it can intensify the sun’s rays.
• Protect your eyes with sunglasses, your face with a hat and your arms with long sleeves.
• Don’t forget your neck! Try to wear collared shirts when possible

Sunburn and Sun Poisoning

Anyone can receive a sun burn within 15 minutes of being exposed to UV rays without protection. Redness and discomfort from a sunburn can take a few hours to present itself, often times leading to a more severe burn, as people are not prompted to seek shade or put on sunscreens. But what is sun poisoning? Sun poisoning or a severe sunburn occurs over an extended period of over-exposure to the sun, and has the following symptoms:

• Skin redness and blistering
• Pain and tingling
• Swelling
• Headache
• Fever and chills
• Nausea
• Dizziness
• Dehydration

So, what do you do if you sunburn has progressed into sun poisoning?

• Get out of the sun.
• Take a cool (not cold) shower or bath or apply cool compresses.
• Drink extra fluids for a few days.
• Take ibuprofen or acetaminophen to relieve pain.
• Use aloe gel or a moisturizer.
• Completely cover sunburned areas when going outside.

It is also very important to seek immediate medical attention at an ER or urgent care location such as CareSpot when the following symptoms present themselves:

• Blistering of the skin
• Severe Sun Burn of a Large Area of Skin
• Pain on the affected area
• Facial swelling
• Fever and chills
• Upset Stomach
• Headache, confusion or faintness
• Symptoms of dehydration

Can Food Help Protect Your Skin?

A number of studies indicate that the foods we eat may have nutritional benefits that include a degree of protection against sun damage. While healthy foods are never a substitute for sunscreen use, they might provide benefits for your skin in the sun in addition to sunscreen.

For instance, tomatoes contain lycopene, which has been shown to make some individuals less susceptible to sunburn. In one study, people who ate tomato paste daily for 10 weeks suffered fewer sunburns than the control group.

What other foods might boost skin health? Nuts are high in omega-3 fatty acids, which keep skin healthy. Blueberries, cacao powder and leafy greens provide antioxidants, which may also help your skin repair itself after a sunburn.

Although this link is not yet ironclad, there is hardly a downside to eating more fruits and vegetables — you’ll gain extra vitamins and minerals while also potentially gaining some valuable skin benefits!

Wear your sunscreen and enjoy this beautiful summertime sun. If you do get burnt and need medical help, contact CareSpot. We treat burns, rashes and many other ailments.