9 Things to Watch for During Sun Exposure

Medically Reviewed by Dan Brennan, MD on August 17, 2021

‌The sun has both benefits and dangers for your health. On the one hand, you need sun exposure to make vitamin D for your bones and teeth. On the other hand, the sun burns your skin and causes wrinkles and skin cancer. For this reason, there are things you should do to protect your skin during sun exposure.

1: Use Enough Sunscreen

Sunscreen is the most important sun product, but using the right amount is also important because too much unprotected sun exposure causes sunburn and skin damage. Most people only use about 25% to 50% of the amount they should. ‌

‌As a general rule, adults should apply two teaspoons of sunscreen to cover their head, arms, and neck, or two tablespoons to cover their whole body while wearing a swimsuit. Sunscreen should be applied liberally and often.

2: Wear Broad Spectrum Sunscreen

The sun has two types of rays that can damage your skin: UVA and UVB. UVA rays cause photoaging, leading to sun spots and wrinkles, and UVB rays cause sunburns. Too much sun exposure to both UVA and UVB rays can cause skin cancer.

In order to protect your skin from both types, you should use broad spectrum sunscreen. Make sure to double check the label before applying.

3: Use the Correct SPF

SPF, or sun protection factor, tells you how well the sunscreen protects you from UVB rays. This is calculated by how long it takes skin with sunscreen to burn compared to skin without sunscreen. ‌

You should wear at least 30 SPF sunscreen. Higher numbers only give slightly more protection, but they last the same amount of time as the lower SPFs. Lots of sunscreens also have less SPF than what is advertised, which means it's even more important to apply the right amount.

4: Don’t Use Old Sunscreen

Like everything else, sunscreen also loses its strength over time. While the Food and Drug Administration states that sunscreens must last for at least three years, make sure to check the date on your bottle. Throw out anything that’s expired or that you’re not sure how long you’ve had. 

5: Be Aware of the Time of Day You Are Outside

The sun is strongest from 11 am to 3 pm. Avoid being in the sun during these times or stay in the shade if you have to be outside. Keep small babies under six months out of direct sunlight and have children get a break in the shade too. 

6: Wear Sunglasses and Light Clothing

You should also use other methods to protect your skin besides sunscreen — especially for children. Wear sun-protective clothing made with UV-resistant fabric and a wide-brimmed hat to protect your face and neck. UV light can also damage your eyes, so also make sure to wear sunglasses.

7: Don’t Exercise in High Temperatures

Heat exhaustion happens when you’re exercising in high heat and your body can’t cool down properly. It happens over time and after long periods of exercise. ‌

If you feel faint, clammy, have a headache, or feel sick after sun exposure, cool your body down and sip on cold water or a sports drink. If you don’t get better after an hour — or you get worse — see a doctor. Heat exhaustion can lead to heatstroke, which is a life-threatening condition. 

8: Stay Hydrated

Sun exposure can make you hot and cause you to sweat to help cool your body down. If you lose more fluids from sweating than you’re able to take in by drinking, you can become dehydrated. This dehydration then stops your ability to sweat and cool off and can lead to heat exhaustion.‌

To prevent dehydration during sun exposure, make sure to drink plenty of fluids and take it easy when it’s hot outside. Plan your exercise or events during the cooler times of the day.

9: Reapply Sunscreen After Swimming and Sweating

You might notice that you have a sunburn after swimming. This commonly happens because water washes sunscreen off, and because you’re cooled down you’re not aware that your skin is burning. Water also reflects light, which can cause a sunburn.  ‌

The solution is to wear water-resistant sunscreen. It generally lasts up to 40 minutes in the water, though some excellent products might last as long as 80 minutes. If you’re swimming, exercising, or simply sweating because it’s hot, you’ll need to re-apply your sunscreen often.

Bottom Line on Sun Safety

Sunburn is the most common summer injury and sun exposure can lead to heat-related illnesses. Protect yourself and your children by wearing sunscreen, drinking lots of fluids, and cooling off in the shade or air conditioning. 

Show Sources


American Academy of Dermatology Association: “5 common sunscreen mistakes - and how to avoid them.”

CDC: “CDC’s Eight Tips for Safe and Healthy Summertime Work and Play.”

Environmental Health Perspectives: “Benefits of Sunlight: A Bright Spot for Human Health.”

Mayo Clinic: “Best sunscreen: Understand sunscreen options,” “Heat exhaustion.”

NHS: “Sunscreen and sun safety.”

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