Think sunscreen season is just for warm summer months? Think again. As any dermatologist, esthetician, skin nerd or beauty influencer will tell you, sunscreen with a rated SPF should be worn all year round.

SPF is a rating of how much solar energy (UV radiation) is required to produce sunburn on protected skin (i.e., in the presence of sunscreen) relative to the amount of solar energy required to produce sunburn on unprotected skin. As the SPF value increases, sunburn protection increases.

Our teenage selves might scoff at this. But without protection, the skin is vulnerable to a number of potential negative outcomes ranging from sunburn to skin cancer.

“Ultraviolet light creates inflammation in the skin,” explains Dr. Anne Chapas, a board certified dermatologist and the medical director of UnionDerm in New York City. “In lighter skinned individuals, skin will begin to redden shortly after you are exposed to the sun, leading to sunburn and other effects such as blotchiness, rosacea or spider veins as well as lasting long term sun damage.”

Fortunately, there are ways to prevent these effects.

First and foremost, the importance of wearing SPF - even if you’re indoors most of or all day - is key. Second, beyond aisles full of sprays, lotions, and gels: knowing which type of sunscreen (mineral vs. chemical) does what and how often you should re-apply it is imperative.

For a quick SPF refresh full of useful and applicable information, Dr. Chapas answered our burning (pun intended!) questions.

Read on to learn more about how to prepare for sun exposure during the summer (and all other months, too). It might save you a bad sunburn or longer-term sun/skin damage.

What SPF is best for your face?

The best sunscreen is the one you like to wear every day. There are many formulations, some in moisturizers, some without. Ask your dermatologist for samples to find the one that best suits your skin type and personal preferences.

What SPF is best for the body?

Body sunscreen has the same ingredients as face sunscreen. The formulations for the body tend to spread easier over larger surface areas.

What are the differences between chemical sunscreen and mineral sunscreens? And which is better for you?

The key difference between these types of sunscreens is how they block sun rays. Mineral sunscreens sit on the surface of your skin and act as a shield, while chemical sunscreens sink into the top layer of the skin and act like a sponge. If you’ve got questions about which ones to use and when, talk to your dermatologist or health care practitioner.

How much sunscreen do we need for our face? How about our bodies?

Most sunscreens come with instructions for how to apply – and how often to reapply. So start there. When applying it on your face, it’s extremely important to cover your entire face as well as your neck, behind your ears, temples and hairline.

What SPF number is best?

The American Academy of Dermatology Association recommends using broad-spectrum sun protection with an SPF of 30 or higher to properly protect from sun damage. Broad spectrum SPF protection means you’re using a sun care product that helps protect against both UVA and UVB rays. UVA rays penetrate deep into the layers of the skin and can lead to premature signs of aging, including visible fine lines and wrinkles. UVB rays are primarily responsible for causing sunburn because these rays penetrate the outer layer of skin and cause damage to skin cells.

But back to SPF. SPF stands for Sun Protection Factor. The SPF number indicates the level of protection against ultraviolet (UV) B rays. Sunscreens with a higher SPF offer greater protection from the sun.

How often do people need to apply sunscreen if they are outside? How about inside?

Unless otherwise directed on your sunscreen care instructions, you should re-apply sunscreen every two hours if you’re outside and every four to six hours if you’re inside. If you’re sitting indoors in direct sunlight, you’ll want to apply more frequently like you would if you were outdoors.

What clothing do you recommend for sun protection?

For an extra layer of protection, consider wearing lightweight, long-sleeved shirts and pants if possible, UV protected sunglasses and a wide-brimmed hat or visor.

Now you know what time it is… lather on and reapply as directed!