Teenagers and people in their 20s are more likely to get sunburned and sit out during the hottest part of the day than those who are older, research shows.
More than half (54%) of 16 to 30-year-olds go out into the sun daily during summer, compared with 44% of those aged 31 to 45, a survey found.
Almost one in five (17%) never avoid the hottest part of the day (11am to 3pm), compared with 9% of 31 to 45-year-olds, 6% of those aged 46 to 60 and 7% of over-60s.
When asked if they allow their skin to burn, 19% of younger people do so more than once a year, compared with 6% of those aged 31 to 60 and 3% of over-60s.
Almost a quarter (23%) of younger people also never wear a cover-up or hat to protect their skin, compared with 8% of those in their 30s and early 40s.
Even young people who have experienced skin cancer or had a family member with the disease are no less likely to go out in the sun or burn than those with no history.
The study of 1,000 people is being presented at the British Association of Dermatologists' (BAD) annual conference in London.
Cancer Research UK figures show that rates of malignant melanoma, the most deadly form of skin cancer, have tripled among those aged 15 to 34 since the late 1970s.
Then, there were 1.8 cases of melanoma per 100,000 people in this age group, rising to 5.9 now.
Nina Goad, from BAD, said young people could feel under pressure to look tanned, while older people may take into account the ageing effects of the sun.
She added: "With so much education - both in schools and in publicity campaigns - aimed at young people, it is a real worry that this age group are still either ignorant to, or choosing to ignore, sun safety messages."
Dr Antonia Lloyd-Lavery, from Oxford Radcliffe Hospitals NHS Trust dermatology department, said: "Our results indicate that younger patients are less likely to practise safe sun exposure.
"Furthermore, our results suggest that those with a personal or family history of skin cancer may not have received critical education on safe sun exposure from the medical profession.
"UK-based health awareness programmes should therefore particularly target younger age groups.
"In addition, healthcare professionals must ensure that opportunities are taken to reinforce the importance of safe sun exposure among patients."