By the time children can run around, most parents are reasonably conscientious about slathering the youngsters with sunscreen when they're outside for any length of time.
But sun protection for babies can be more daunting. One study found that 54 per cent of children in the US got a sunburn or deep tan by their second summer; 22 per cent in their first year.
Just one blistering sunburn as a child more than doubles a person's odds of developing melanoma later in life. And 60 per cent to 80 per cent of a person's lifetime sun exposure comes in the first 18 years of life.
"Children should not be getting sunburned at any age," said Perry Robins, president of The Skin Cancer Foundation in the US.
"Parents need to be extra vigilant about sun protection all the time."
Hard as it is, infants six months and under simply have to stay out of the sun. Their skin has very little melanin, the pigment that gives skin colour and also provides some sun protection.
Although beach umbrellas, shade tents, awnings and hats provide a shield from the sun, they may not always be enough - just the reflection of sun from sand or a playground can fry sensitive skin. It is best to go on outings before 10am and after 4pm, when ultraviolet rays are weaker.
When you do go out, dress your infant in lightweight clothing that covers the arms and legs and a wide-brimmed hat that covers the face, neck and ears. The stroller or carrier should have a shade cover, as should any untinted rear windows of a car on a ride of any distance.
While there are concerns that infant skin before six months of age may be too sensitive for sunscreens, the Cancer Council of Australia advises that there is no evidence that using sunscreen on infants is harmful. It recommends that a SPF30+ broad spectrum water resistant sunscreen should be applied to any small areas of skin that cannot be protected by clothing (such as face, ears, backs of hands).
Sunscreen will need to be applied 20 minutes before going outside and reapplied every couple of hours or more often if it has been wiped or washed off.
Skin cancer prevention advocates also note that while people with darker skin are less susceptible to skin cancer - by some estimates, melanin levels in the skin of some African-Americans is equal to an SPF 13 - they still face considerable risk from skin cancer.
According to one recent study, incidence of melanoma, the deadliest form of skin cancer, rose 32.4 per cent among Latinos between 1992 and 2005. Other studies suggest that by the time Hispanics are treated for melanoma, they are more likely to have thick tumours with a poor prognosis compared to Caucasians diagnosed with the same cancer.
Among African-Americans, the five-year survival rate with melanoma is 59 per cent, compared to 85 per cent in whites.
Researchers think other factors, including genetics and prior injuries to the skin, may drive skin cancer - particularly melanoma - in many people of colour more than sun exposure does. Still, skin colours can vary widely within ethnic groups, and those with lighter skin remain at higher risk.
At least partly because the skin cancer risk in people of colour is thought to be lower, and since tumours are likely to develop in less obvious places, such as the palms of the hand, soles of the feet or in the mouth, doctors may be less careful in screening them and have more difficulty identifying cancers, experts note.
- AAP