Sun exposure is associated with numerous positive effects, including the body’s own production of vitamin D. However, vitamin D synthesis depends on many factors such as skin type, geographic location, season, time of day, and the intensity of UVB radiation. Studies also show that adequate vitamin D levels cannot always be ensured through sunlight alone, which is why the American Academy of Pediatrics recommends obtaining vitamin D preferably through diet or supplementation.

At the same time, ultraviolet (UV) radiation poses a significant health risk, especially for infants and young children. Due to their still immature skin barrier, babies have reduced natural protection against UV radiation. Even short periods of intense sun exposure can lead to sunburn, dehydration, or heat-related illnesses. In addition, high UV exposure during childhood is considered a major risk factor for the later development of skin cancer. For these reasons, dermatological societies recommend consistently protecting infants and young children from intense sun exposure and using a multi-layered sun protection strategy.

UV radiation and its health effects 

Ultraviolet radiation from the sun is divided into UVA, UVB and UVC rays. While UVC radiation is almost completely absorbed by the ozone layer, UVA and UVB rays reach the Earth’s surface.

UVA rays penetrate deeply into the skin and contribute to skin aging as well as indirect DNA damage. UVB rays have higher biological activity and are primarily responsible for sunburn. Both types of radiation contribute to the development of skin cancer. In particular, intense UV exposure in early childhood increases the risk of melanoma and other forms of skin cancer later in life.

Avoiding direct sun exposure

International medical organizations recommend that infants under six months should not be exposed to direct sunlight at all. Older infants and toddlers should also avoid intense sun exposure, especially during peak UV hours in Central Europe, typically between 11:00 a.m. and 3:00 p.m.

Outdoor activities should preferably take place in the early morning or late evening. It is important to note that UV radiation is not limited to direct sunlight. Reflections from water, sand, concrete, or snow can further increase overall UV exposure.

Clothing as the primary protective measure

Clothing is the most effective physical barrier against UV radiation. Loose-fitting garments made of tightly woven fabrics that cover as much skin as possible are recommended. Textiles with a certified ultraviolet protection factor (UPF) are particularly suitable. Clothing with a UPF of 50 or higher blocks the vast majority of UV radiation and provides excellent protection.

In addition, a wide-brimmed sun hat or legionnaire-style hat should be worn to protect the face, ears, and neck from direct sunlight. Sunglasses with certified UV-400 protection also help protect the sensitive eyes from UV-related damage.

Role of sunscreen

Sunscreen should be considered only a complementary protective measure for infants and young children. For infants under six months, routine use of sunscreen is generally not recommended due to their highly sensitive skin. From six months of age onward, broad-spectrum sunscreens with at least SPF 30, preferably SPF 50, may be applied to uncovered skin areas.

Sunscreen should be applied about 20 to 30 minutes before sun exposure and reapplied at least every two hours, as well as after swimming or heavy sweating. A patch test on a small area of skin is recommended before first use.

Protection against overheating and heat stress

In addition to UV radiation, high ambient temperatures pose a significant health risk. Infants have an underdeveloped thermoregulation system and are more susceptible to heat stress than adults.

Strollers should not be completely covered with blankets or cloths, as this can quickly lead to dangerous heat buildup. Instead, integrated sun canopies or umbrellas that provide shade while allowing sufficient air circulation are recommended.

Furthermore, babies should never be left unattended in a parked vehicle, as temperatures inside a car can reach life-threatening levels within minutes.

Prevention of dehydration

Maintaining adequate hydration is especially important on hot days. Due to their larger body surface area relative to body weight, infants lose fluids more quickly than adults. Recommendations are based on the infant's age (NHS, 2024):

0 - 6 months: 

• Excusively breastfed babies normally do not need additional water.
• In hot weather, they often want to be breastfed more frequently, which covers their fluid needs.
• During hot weather, they may breastfeed more frequently, which helps meet their fluid requirements.
• Formula-fed infants may, after consultation with a paediatrician, be given small amounts of boiled and cooled water in addition. 

6 - 12 months:

• Once complementary feeding is introduced, additional water can be offered from a cup or beaker.
• breast milk or infant formula remains the main source of nutrition and hydration throughout the first year of life.

> 12 months:

• Water should remain the main drink.
• Breast milk or cow’s milk can also be offered.
• Water-rich foods such as watermelon, cucumbers, or berries can further support adequate hydration.

Measures for cooling during high outdoor temperatures

To prevent heat-related illnesses, living and sleeping areas should be kept as cool as possible. Blinds or curtains can be closed during the day to reduce excessive indoor heat buildup. Fans may improve air circulation, but they should not be directed straight at infants.

Lightweight, breathable clothing as well as lukewarm baths can also help support temperature regulation. The recommended room temperature in an infant’s bedroom is between 16 and 20 °C.

The protection of infants and young children against UV radiation and heat is based on a multi-layered prevention concept. This includes seeking shaded areas, wearing UV-protective clothing, appropriate head coverings and the careful use of sunscreen as a supplementary measure. Equally important are adequate fluid intake and strategies to prevent overheating.

Early and consistent sun protection behaviour plays a key role in sustainably reducing the risk of UV-related skin damage and skin cancer later in life.

Sources: 

Herbst, M. C. (2021). Fact Sheet on Being SunSmart with Infants,Toddlers and Children. Source

Jindal, A. K., Gupta, A., Vinay, K., & Bishnoi, A. (2020). Sun Exposure in Children: Balancing the Benefits and Harms. Indian Dermatology Online Journal, 11(1), 94. Source

NHS. (2024). Keeping your baby safe in the sun. Nhs.Uk.. Source

Queensland Government. (2024, Januar 24). How to keep your baby safe from the sun [Text]. corporateName=The State of Queensland; jurisdiction=Queensland. Queensland Health. Source