But Why: A Podcast for Curious Kids

Episode: Why Do We Need to Use Sunscreen?
Host: Jane Lindholm
Guest: Dr. Jeff Yu, Pediatric Dermatologist
Release Date: June 13, 2025

Introduction to Sun Safety

In this episode of But Why: A Podcast for Curious Kids, host Jane Lindholm delves into the essential topic of sun safety with the expertise of Dr. Jeff Yu, a pediatric dermatologist from Massachusetts General Hospital. As summer approaches, the discussion centers around the importance of protecting our skin from the sun's harmful ultraviolet (UV) rays.

Understanding Sunburn

Dr. Jeff Yu begins by explaining what a sunburn is and its effects on the skin.

Dr. Jeff Yu (02:05): "A sunburn is something that happens on your skin after your skin has been exposed to a lot of sunlight... your skin turns red, it hurts when you touch it, and it feels hot."

He highlights that while short-term sunburns heal naturally, repeated exposure increases the risk of skin cancer later in life.

Dr. Jeff Yu (05:26): "If you're someone who grew up getting sunburns over and over again every single summer, this leads to many problems when you get a little bit older... one of the first things that we as dermatologists really worry about is the increased risk of developing skin cancers."

The Science of Tanning

Jane introduces the concept of tanning, a common response to sun exposure that differs from sunburn.

Jane Lindholm (06:27): "Sometimes instead of your skin turning all red and itchy, it just gets a little darker. People call this a tan."

Dr. Yu explains the biological mechanism behind tanning, emphasizing that it's the skin's way of producing melanin to protect against UV rays.

Dr. Jeff Yu (06:47): "Melanocytes... produce melanin that is supposed to be used to protect your skin against sunlight. The more melanin you make, the darker your skin becomes."

He cautions against seeking a tan as a protective measure, comparing excessive sun exposure to over-toasting bread, which can lead to burns.

Jane Lindholm (08:24): "Is a similar thing happening with our skin?"
Dr. Jeff Yu (08:24): "Absolutely... even a little bit of exposure... you are still damaging your cells to a certain degree."

The Role of Sunscreen

The conversation shifts to sunscreen, a vital tool in sun protection. Dr. Yu describes sunscreen as "invisible armor" that shields the skin from harmful UV rays.

Dr. Jeff Yu (08:50): "Sunscreen... is just a type of lotion that you put on your skin to protect your skin from the light... it's almost like putting on invisible armor."

Types of Sunscreen: Chemical vs. Mineral

Dr. Yu elaborates on the two main types of sunscreen: chemical and mineral.

Dr. Jeff Yu (10:19): "Chemical sunscreens like to go on very clear... Mineral sunscreens are the ones that tend to go a little bit whiter."

He explains how chemical sunscreens absorb UV rays, while mineral sunscreens reflect them, using ingredients like zinc and titanium.

Dr. Jeff Yu (10:19): "Mineral sunscreens... deflect the light... preventing the cells underneath it from coming in contact with the ultraviolet light."

Jane adds a fun perspective on mineral sunscreens, noting their availability in various colors, which can make applying sunscreen enjoyable for kids.

Jane Lindholm (11:36): "We have a lot of fun with some colorful mineral sunscreen... to make patterns that are pink or blue or yellow and green."

Protecting Eyes with Sunglasses

The discussion progresses to eye protection, addressing the importance of sunglasses.

Dr. Jeff Yu (16:00): "Sunglasses... protect the skin around your eyes and your actual eyes from the sun... they filter out harmful ultraviolet light."

Jane humorously remarks on the discomfort of sunscreen in the eyes, underscoring sunglasses as a superior protective measure.

Jane Lindholm (16:44): "I hate it when sunscreen gets in my eyes. It stings. So sunglasses are a much better way of doing it."

She further explores why sunglasses alter our perception of colors and visibility.

Dr. Jeff Yu (17:12): "Sunglasses are made out of special lenses that are tinted or colored... they filter ultraviolet light, making what you see safer for your eyes."

Importance of Hydration

Hydration emerges as another critical aspect of summer safety. Dr. Yu explains the body's reliance on water and the dangers of dehydration.

Dr. Jeff Yu (18:48): "Your body is mostly made out of water... when you sweat, you're losing water from your body... if you lose too much water, you can get dehydrated."

He details the symptoms of dehydration and its impact on physical performance and overall health.

Dr. Jeff Yu (18:48): "When you get dehydrated, a lot of bad things can happen... you might start to feel dizzy, you might start getting a headache, you might start to feel sleepy."

Balancing Sun Exposure

In addressing concerns about sun safety causing unnecessary fear, Dr. Yu reassures listeners that the sun itself is not dangerous when proper precautions are taken.

Dr. Jeff Yu (20:42): "I absolutely do not think you need to be afraid of the sun... practicing sun safety is the best way to go about making sure that you are enjoying the summer."

He advises balancing sun exposure by seeking shade during peak sunlight hours (10 AM to 4 PM), reapplying sunscreen regularly, and wearing protective clothing.

Dr. Jeff Yu (20:42): "Find areas under trees... wear a hat... make sure that you are using sunscreen... wear clothing that offers you some sort of ultraviolet protection factor."

Conclusion and Recommendations

Jane wraps up the episode by summarizing the key points discussed with Dr. Yu. She encourages listeners to apply sunscreen, wear hats and sunglasses, stay hydrated, and enjoy the outdoors safely.

Jane Lindholm (22:40): "Thanks to Dr. Jeff Yu... put on some sunscreen, grab a hat and a water bottle and go play outside."

She also invites listeners to share their summer solstice celebrations and submit questions for future episodes.

Notable Quotes:

• Dr. Jeff Yu (05:26): "If you're someone who grew up getting sunburns over and over again every single summer, this leads to many problems when you get a little bit older."

• Dr. Jeff Yu (08:50): "Sunscreen... is almost like putting on invisible armor to protect your skin from the harmful effects of sunlight and ultraviolet rays."

• Dr. Jeff Yu (16:00): "Sunglasses... are able to filter ultraviolet light... preventing the cells underneath it from coming in contact with the ultraviolet light."

• Dr. Jeff Yu (20:42): "I absolutely do not think you need to be afraid of the sun... practicing sun safety is the best way to go about making sure that you are enjoying the summer."

This episode of But Why effectively educates young listeners on the importance of sun safety, providing practical tips and scientific explanations to empower kids to protect themselves while enjoying the summer outdoors.