The sun’s rays are strongest between 10:00 am and 4:00 pm, which is when most of us want to spend time outdoors. However, this window of intense sun can also cause harm to your little one’s still-maturing skin.

Avoiding the sun during the middle of the day is the best way to prevent exposure that can damage baby and toddler skin (and potentially lead to skin cancer later in life). When you are outside, covering your child’s skin in lightweight clothing is a great way to protect them. For any exposed skin, the next step is applying sunscreen.

With so many types of sunscreen available, how do you know which one is right for your child?

Here’s what you need to know:

Step 1: Talk with your pediatrician.

Learn about the best sunscreen options for your little one from your pediatrician, who can offer recommendations based on medical history. If your child has skin sensitivities or allergies, or is taking any medications, your pediatrician may suggest a specific type of sunscreen to avoid potential side effects.

Step 2: Understand SPF.

SPF stands for “Sun Protection Factor.” It measures the length of time sunscreen should offer sun protection. The higher the SPF number, the longer the shield, although this isn’t an exact science.

Babies and toddlers should use a sunscreen with at least 15 SPF, although you can go up to 50 SPF. For babies with sensitive skin, your pediatrician might recommend a sunscreen formulated for sensitive skin.

High SPF sunscreen won’t necessarily keep your child safe in the sun all day. Even the best sunscreen doesn’t protect against all the sun’s rays, so it’s crucial to keep your baby covered up as much as possible and reapply sunscreen every one to two hours.

Step 3: Know what to look for and avoid.

Most sunscreen products are tested for safety, but it’s still a good idea to know what you’re getting in each bottle. The American Academy of Pediatrics (AAP) recommends avoiding sunscreen with oxybenzone, a chemical that may affect hormone levels. The Environmental Working Group (EWG) also notes that a preservative called methylisothiazolinone may be harmful to those with skin sensitivities or allergies.

What you do want to find is the label “broad-spectrum” somewhere on the bottle. Broad-spectrum sunscreen protects against both UVA and UVB rays, which are different types of radiation from the sun that damage the skin.

Step 4: Learn how to apply it.

For babies, use just a small amount of sunscreen on their face, ears, hands, and other areas not covered by clothing. You can be more liberal with your toddler’s sunscreen, but be careful around the mouth and eyes.

Apply sunscreen 15 to 30 minutes before heading outside. Then, remember to frequently reapply, especially if your little one goes swimming, plays at a water table, or sweats.

Step 5: Look for signs of irritation

Irritation from sunscreen can happen to anyone, but immature skin makes babies and toddlers more vulnerable to adverse side effects. Some warning signs to look for after wearing sunscreen include:

• Red or blotchy skin
• Itchy skin
• Blistering skin
• A stinging or burning feeling
• Painful skin

Your baby or toddler may not be able to tell you if they’re feeling pain, so watch for signs of discomfort, such as extreme irritability or excessive crying. Call your pediatrician immediately if you notice any problems after applying sunscreen.

Don’t forget: Staying out of direct sun as much as possible is the best skin protectant for your baby or toddler, but covering up with the right sunscreen is an excellent backup plan when you can’t avoid it.