Sunburn: What should you do when your skin turns red?

Sunburn is an acute injury caused by ultraviolet radiation. The skin typically becomes red, hot, sore and stinging a few hours after receiving more sun than it could tolerate. The priorities are to get out of the sun, cool the skin gently and avoid further UV exposure while it heals. This guide gives you a simple plan and draws a clear line between first aid and cosmetic skincare.

Is it sunburn or sun rash?

Sunburn is caused by too much UV radiation and mainly appears as heat, redness, soreness and stinging. A more severe burn may develop blisters. Symptoms often become noticeable four to six hours after being in the sun.

Sun rash, also known as polymorphic light eruption, is a sensitivity reaction that often itches and causes small bumps or blisters on sun-exposed skin. You can develop sun rash without being sunburnt. If itching and a rash are the main symptoms, read our separate guide to sun rash symptoms and prevention.

First aid for mild sunburn

You can usually ease a minor sunburn yourself:

1. Get out of the sun immediately and keep the affected skin covered for the next few days.
2. Cool it with a cool bath or cool, wet cloths. Do not put ice directly on the skin.
3. Drink water, especially if you have also been hot or sweating heavily.
4. Leave blisters alone, and do not scratch the skin or pull off peeling skin.
5. Wear loose, soft clothing that does not rub against the affected area.

The Danish Patient Handbook on sundhed.dk recommends cooling with water and using moisturiser, and also explains when to contact a doctor.

What to avoid on hot, damaged skin

Avoid very hot water, vigorous scrubbing, exfoliation, fragranced products and active ingredients that sting. Oil is not the first step while the skin still feels hot either: a dense layer of oil can feel uncomfortable and replaces neither cooling nor a medical assessment.

Never use skincare as a substitute for treatment. If the skin is open, weeping or covered with blisters, do not experiment with cosmetic products.

When does ByLykke skincare fit in?

Once the skin has cooled, is intact and can tolerate touch, a simple fragrance-free moisturiser may feel comfortable. Test it on a small area first and stop if it stings or makes the redness worse.

• ByLykke Colostrum Lotion is a light, fragrance-free body lotion that is easy to spread over arms, legs and shoulders.
• ByLykke Colostrum Cream provides a richer layer of moisture for the face, neck and smaller dry areas.

These products are cosmetic skincare. They do not treat sunburn or sun rash, have no documented sun protection factor and should only be used on intact skin. Wait until the acute heat and irritation have passed before using a plant oil. You can also read why raspberry seed oil cannot replace sunscreen.

Prevent the next sunburn

The best plan is to prevent another burn. Seek shade when UV levels are high, wear covering clothes, a wide-brimmed hat and sunglasses, and use plenty of sunscreen on skin that clothing does not cover. The Danish Cancer Society recommends at least SPF 30; see its sunscreen fact sheet.

Apply sunscreen after your usual skincare and follow the product directions. Reapply after swimming, heavy sweating and towel drying. A tan is not a safe way to “harden” the skin.

When should you seek medical advice?

Contact a doctor if there are many or large blisters, severe or worsening pain, fever, intense itching, an increasing rash or signs of infection. Seek urgent help for drowsiness, confusion, dizziness, nausea or any other change in general condition, as sunburn can occur together with dehydration or heatstroke.

Take particular care with young children and when a large area is affected. If the reaction started after new medication or repeatedly occurs after very little sun, a doctor or pharmacist should also assess whether your skin has become photosensitive.

Frequently asked questions

How long does sunburn last?
A mild sunburn often settles over a few days. Protect the skin completely from further sun while it heals.

Can I apply cream straight away?
Cool the skin first. Once it is intact and no longer feels hot, you can carefully try a mild, fragrance-free moisturiser.

Are sunburn and sun rash the same thing?
No. Sunburn is UV damage; sun rash is a sensitivity reaction in which itchy bumps or a rash are usually more prominent.

Can ByLykke products be used as aftersun?
They are ordinary cosmetic moisturisers, not medicines or tested aftersun products. Use them only on cooled, intact skin if they feel comfortable.

This article provides general information and cannot replace individual advice from a doctor or pharmacist.