No one wants to deal with cold sores, but unfortunately, they are a reality for many of us. And while there are a number of different triggers that can cause cold sores (stress, fatigue, hormonal changes, etc.), did you know that sun exposure is also a major trigger? In fact, according to a recent study, nearly 50% of people with cold sores said that sun exposure was a major trigger for them. 

Read on to learn more about “Can you get cold sores from the sun?” and how you can protect yourself from sun exposure. We’ll also discuss how to treat a cold sore if you do happen to get one. 

What are Cold Sores, and How Do People Get Them?

Cold sores, also called fever blisters, are small, fluid-filled blisters that usually occur in a cluster. They can last up to two weeks and are usually uncomfortable. The Herpes Simplex Virus (HSV) is what causes cold sores (HSV).

HSV is a contagious virus that can be spread from person to person through skin-to-skin contact. People with HSV often get cold sores on their lips, but the sores can also occur on other parts of the body, including the face. 

Factors that Increase Risk of Cold Sores in the Sun

While cold sores can’t be caused directly by the sun, there are some factors that can increase the risk of getting a cold sore from sun exposure. These include:

UVB Exposure

UVB rays are the kind of rays that cause sunburns. They are also the main culprit when it comes to triggering cold sores. That’s because UVB rays can damage the DNA in our skin cells, which then makes it easier for the herpes virus to enter our cells and cause an outbreak. 

Hotter Temperatures

It’s not just the UVB rays that can increase our risk of developing cold sores; hotter temperatures can also be a trigger. This is because when our bodies get too hot, we sweat—and when we sweat, our pores open up and become susceptible to viruses like the Herpes Simplex Virus. 

Dry Skin

Dry skin is yet another factor that can increase our risk of developing cold sores in the sun. That’s because when our skin is dry, it cracks and becomes vulnerable to infection. And since the Herpes Simplex Virus loves to live in warm, moist environments, dry skin provides the perfect opportunity for an outbreak. 


Windburn is yet another type of exposure that can damage our skin and make us more susceptible to developing cold sores. When we experience windburn, it literally strips away the protective barrier on our skin, leaving us exposed to infections like the Herpes Simplex Virus. 


Finally, immunosuppression is yet another factor that can increase our risk of developing cold sores in the sun. When we are immunosuppressed, our bodies are unable to fight off infections as effectively—which means we’re more likely to develop cold sores if we’re exposed to the Herpes Simplex Virus. 

Symptoms of Cold Sores Associated with Sun Exposure 

Cold sores usually start with a tingling sensation on the lips followed by redness and swelling; this is called prodrome. During prodrome, you may also experience fatigue, headaches, and muscle aches. 

One or more blisters may then form, filled with clear or cloudy fluid. The blister will eventually break open and leak fluid. After a few days, the blister will crust over and heal. 

In some cases, cold sores may also be accompanied by fever, sore throat, and swollen lymph nodes. 

How to Treat Sun-Induced Cold Sores?

If you suspect that your cold sore was caused by sun exposure, it’s important to treat it as soon as possible. Here are a few tips for treating sun-induced cold sores:

Home Remedies

There are several home remedies that can help reduce the pain and healing time of a cold sore. These include applying ice to the affected area or aloe vera gel, using a cold compress on the affected area, and drinking plenty of fluids to help your body fight off infection. 

OTC Treatments for Cold Sores

There are also several over-the-counter medicines that can help reduce the pain and healing time of a cold sore. These include antiviral creams such as acyclovir and docosanol. These creams can be applied directly to the cold sore several times a day for up to 10 days. 

Prescription Medications for Cold Sores

If home remedies and OTC treatments for cold sores aren’t effective, your doctor may prescribe a stronger antiviral medication. These medications can be taken orally or intravenously and are usually more effective than OTC treatments. 

How to Reduce Your Risk of a Sunlight-Triggered Outbreak?

Avoid Sun Exposure During Peak Hours

The sun’s ultraviolet (UV) rays are most intense between 10 a.m. and 4 p.m., so it’s best to avoid being outdoors during those hours if possible. If you must be outside, try to stay in the shade as much as possible. 

Wearing Protective Clothing

Wear clothing that covers your skin, including long-sleeved shirts, pants, a hat, and sunglasses. UV-blocking fabrics are available that can provide additional protection from the sun’s harmful rays. 

Wear Sunscreen

Apply sunscreen with an SPF of 30 or higher to all exposed skin every two hours, even on cloudy days. Be sure to reapply after swimming or sweating. 

Drink Plenty of Fluids

Drink eight glasses of water per day to help keep your skin hydrated and healthy. This will help prevent dry skin, which can make you more susceptible to a cold sore outbreak. 


While sun exposure is a common trigger for cold sores, there are ways to protect yourself from getting a cold sore from sun exposure. Wearing protective clothing, applying sunscreen, and drinking plenty of fluids can help reduce your risk of getting a sun-triggered cold sore. You can also check our article on Can Antibiotics Cause Cold Sores?

If you do get a cold sore, there are both home remedies and over-the-counter medications that can help reduce the pain and healing time. 

We hope that this article on “Can you get cold sores from the sun?” has been helpful and informative. Remember to practice sun safety when you are outdoors, and seek medical attention if your cold sores are severe or persistent.