Common symptoms in humans and other animals include red or reddish skin that is hot to the touch or painful, general fatigue, and mild dizziness.

Excessive UV radiation is the leading cause of (primarily) non-malignant skin tumors,[1][2] which in extreme cases can be life-threatening.

When the cells' DNA is overly damaged by UV radiation, type I cell-death is triggered and the tissue is replaced.

[5] Typically, there is initial redness, followed by varying degrees of pain, the severity of which correlates with the duration and intensity of sun exposure.

[citation needed] Other symptoms can include blistering, swelling (edema), itching (pruritus), peeling skin, rash, nausea, fever, chills, and fainting (syncope).

[7] Sunburn can occur in less than 15 minutes in response to sun exposure and in seconds when exposed to non-shielded welding arcs or other sources of intense ultraviolet light.

[1][2][8] Of greatest concern is that the melanoma risk increases dose-dependently proportional to the number of a person's lifetime cumulative episodes of sunburn.

[10] Sunburn is caused by UV radiation from the Sun but may also result from artificial sources, such as tanning lamps, welding arcs, or ultraviolet germicidal irradiation.

People with lighter skin tones and limited capacity to develop a tan after UV radiation exposure have a greater risk of sunburn.

[18] Certain genetic conditions, for example, xeroderma pigmentosum, increase a person's susceptibility to sunburn and subsequent skin cancers.

), each location within the tropic or polar regions receives approximately the same amount of UV radiation over a year.

The most significant risk is at solar noon when shadows are at their minimum, and the Sun's radiation passes most directly through the atmosphere.

[citation needed] The skin and eyes are most sensitive to damage by UV at 265–275 nm wavelength, which is in the lower UVC band that is rarely encountered except from artificial sources like welding arcs.

[citation needed] In recent decades, the incidence and severity of sunburn have increased worldwide, partly because of chemical damage to the atmosphere's ozone layer.

[27] The World Health Organization, American Academy of Dermatology, and the Skin Cancer Foundation have recommended avoiding artificial UV sources such as tanning beds.

Considerations for diagnosis include duration and intensity of UV exposure, topical or systemic medication use, history of dermatologic disease, and nutritional status.

Symptoms common to heat illness and the prodromic stage of acute radiation syndrome like nausea, vomiting, fever, weakness/fatigue, dizziness or seizure can add to further diagnostic confusion.

The stated protection factors are correct only if 2 mg of sunscreen is applied per square cm of exposed skin translates into about 28 mL (1 oz) to cover the whole body of an adult male.

[43] Recommendations are product dependent varying from 80 minutes in water to hours based on the indications and protection shown on the label.

The American Academy of Dermatology recommends the following criteria in selecting a sunscreen:[44] The eyes are also sensitive to sun exposure at about the same UV wavelengths as skin; snow blindness is sunburn of the cornea.

[citation needed] The skin of the feet is often tender and protected, so sudden prolonged exposure to UV radiation can be particularly painful and damaging to the top of the foot.

Several dietary antioxidants, including essential vitamins, are effective in protecting against sunburn and skin damage associated with ultraviolet radiation, in both human and animal studies.

[50][51] Babies and children are particularly susceptible to UV damage which increases their risk of both melanoma and non-melanoma skin cancers later in life.

[52] The WHO recommends that artificial UV exposure, including tanning beds, should be avoided as no safe dose has been established.

Such sources can produce UVC, an extremely carcinogenic wavelength of UV, which ordinarily is not present in normal sunlight, having been filtered out by the atmosphere.

The American Academy of Dermatology recommends the following for the treatment of sunburn:[54] Non-steroidal anti-inflammatory drugs (NSAIDs; such as ibuprofen or naproxen), and aspirin may decrease redness and pain.

[57] Schwellnus et al. state that topical steroids (such as hydrocortisone cream) do not help with sunburns,[56] although the American Academy of Dermatology says they can be used on especially sore areas.