After a long day in the sun, you may discover you have sunburn -- even if you took precautions to protect your skin. While you may be able to see redness or a rash, or feel the tenderness of your skin is right away, blisters may take a bit longer to appear. Normally, blisters occur within a few hours of the burn, but they can develop days after excessive sun exposure [source: Livestrong].
Blisters can range in size based on the severity of your burn. They can also be quite painful, especially on a sensitive area like your lips. Because you're constantly using your mouth, these blisters may be even more irritating and painful when they appear on the lips. As a result, your first order of business may be soothing your discomfort instead of treating your blisters.
Any type of burn will cause inflammation of the skin, which contributes to the pain the burn causes. Taking aspirin, acetaminophen or ibuprofen can help reduce this inflammation and ease some of the discomfort that follows [source: Nissl].
Cooling gels, which often contain soothing aloe vera, corticosteroids or antihistamines, can also be applied to sunburned lips to ease pain and moisturize damaged skin [source: WebMD].
You should also try to reduce pain by avoiding further irritation of your sunburned lips and blisters. Try to limit your sun exposure until the blisters have healed, because further sun damage can lead to more pain. Keep the area dry, cool and free from any possible irritants -- including contact with the blisters [source: Nissl].
Once you have eased some of the pain of your blisters, read on to find several steps you can take at home to help the healing process.