ALTOONA, Pa. (WTAJ) — Wednesday marked an unofficial worldwide heat record, as the average global temperature reached 62.9 degrees Fahrenheit, according to the Associated Press.

With over 38 million Americans facing some kind of heat watch in recent days, staying safe from the warm weather is on the minds of many.

But although the high temperatures might seem like the main focus when it comes to avoiding harm from extreme conditions, your skin is a lot more concerned with the high UV ratings — something sunscreen is crucial in protecting from.

Does sunscreen really matter?

The answer is a resounding “yes.”

Sunscreen is a daily essential in protecting yourself from skin cancer and other forms of skin damage, said the University of Texas MD Anderson Cancer Center.

That includes both the recent record-hot days and those when you aren’t even going outside — even during the wintertime.

If you spend time next to a sunny window or drive during the daytime hours, you’re still likely exposed to rays that can cause skin damage. And even during the coldest weather, radiation from the sun can still make its way to your skin.

MD Anderson Cancer Center recommends making it a habit to apply a broad-spectrum sunscreen with a sun protection factor (SPF) of 30 or higher every morning.

The Center also advises individuals to apply sunscreen 30 minutes before heading outside since the product can take a while to work itself into the skin.

But what does the SPF number mean?

You’ve probably heard of UV rays before — but do you really understand what they are? Or how they’re different than the temperature on any given day? And what does SPF measure anyway?

There are two kinds of ultraviolet rays produced by the sun: UVB and UVA. Ultraviolet-B can cause sunburns and other skin damage, while UV-A can cause skin cancer, according to the MD Anderson Cancer Center.

The SPF number refers to how much of the sun’s UVB rays the product absorbs and reflects from your skin. But a higher number doesn’t necessarily mean you’re better protected.

For example, an SPF 30 product can take care of around 97% of the sun’s burning rays, but an SPF 50 only increases that value by one percentage point.

Although MD Anderson Cancer Center advises that you should always choose an SPF of at least 30, applying sunscreen frequently and liberally — and choosing a product that protects you from both UVA and UVB rays — is more important than applying any specific SPF value.

What kind of sunscreen is the best?

Not all sunscreen is created equal, according to MD Anderson Cancer Center.

An ideal sunscreen should include either zinc oxide or titanium dioxide — two minerals that can protect your skin from both UVA and UVB rays.

According to Piedmont Medical, the presence of these active ingredients designates a product as a physical/mineral sunscreen instead of a chemical sunscreen.

Physical sunscreens rest on top of your skin, which means the product itself is absorbing and reflecting the sun’s rays. On the other hand, chemical sunscreens work their way into your skin, meaning the sun’s rays also travel into your skin before being reflected back out by the SPF.

Although physical suncare is often preferred by dermatologists, chemical SPFs have their advantages, especially for those who are wearing them while swimming or sweating.

Whether you opt for physical or chemical, make sure any sun product is at least SPF 30 and designated as “Broad Spectrum” to ensure you’re getting complete protection.

A product you do want to avoid in any sunscreen is benzene, which has been found to act as a carcinogen, according to MD Anderson.

However, it’s important to keep in mind that UVA rays also are well-known to cause cancer, so don’t let the fear of harmful ingredients stop you from wearing your SPF regularly.

How should I apply sunscreen?

According to MD Anderson, sunscreens typically wear off within two hours of application. And if you’re sweating or swimming them off on a summer day, they could be gone in as little as one hour.

As a rule, apply a golf ball-sized amount of cream sunscreen to every exposed area every two hours. This might seem like too much product, but MD Anderson writes that it’s important in ensuring skin protection.

If you’re opting for a spray sunscreen, make sure to check the packaging for re-application instructions. These products tend to wear off easier and require more frequent usage.

It’s also important to remember to apply SPF to the areas of your body that often get forgotten, such as your ears, feet and the back of your neck.

What else can I do to keep my skin safe?

Although wearing sunscreen is essential, it can’t filter out 100% of the sun’s harmful UV rays.

Here are other ways to minimize your UV exposure on top of wearing sunscreen, according to MD Anderson:

1. Avoid spending long periods of time outside from 10 a.m. until 4 p.m. This period of time is usually when the UV index is highest, so spend your time outdoors early in the morning or evening to avoid mid-day UV rays.
2. Wear other forms of sun protection. These can include lip balm and makeup with SPF protection, a tightly-woven brimmed hat, sunglasses with UV protection and sun-protective clothing.
3. Never use a tanning bed. Whether you wear sunscreen or not, the concentration of UV rays in tanning salons are extremely harmful to your skin, according to MD Anderson Cancer Center. Opt for faux tanning products to instead to achieve the same sun-kissed glow.

For specific skin concerns, you should consult your personal dermatologist.