Healthy Sun Practices
A general rule. Spending 3 to 15 minutes outdoors for light-skinned individuals and 15 to 30 minutes outdoors for darker skin tones in midday, unobstructed sun with 40 percent of your skin exposed will provide most people with a protective vitamin D level (up to 50,000 IU of Vitamin D in the next 24 hours). The Reference Daily Intake (RDI) however, is only 200 to 600 IU of vitamin D per day. Studies suggest 2000 IU per day to have a protective effect, which can be delivered by regular exposure to the sun.
If the ultraviolet index is more than 3 on any given day, you should use sunscreen while you are outside. It is best, however, to use a sun protection factor (SPF) no greater than 15 to gain the benefits of vitamin D–induced sun exposure without burning.
Reapply sunscreen frequently. Sweating and swimming dilute any sunscreen’s effectiveness. Next to using an SPF that is too low or not using any protection, the failure to reapply consistently is the main cause of burning. In intense sun, even if you are not overly physically active, reapply at least every hour.
Don’t rub it in. Rapid absorption of lotion leaves the outer-most layers of skin with reduced SPF. Therefore, dab sunscreen onto sun-sensitive areas first. Wait 60 seconds, then gently reapply sunscreen to these same areas and also evenly cover the rest of your exposed skin.
Keep your skin moisturized and hydrated. Moist skin is far less likely to burn and will tan faster. Moisturize and nourish your skin with creams, lotions, or oils several hours before (to give the moisturizer time to soak in and, if using oil, to reduce the sheen) and also after long sun exposure.
Cool it. If your skin overheats, it can react with a classic heat rash, which can quickly lead to burning. Frequently cool off either with or in the water and reapply sunscreen. Avoid waterproof, sport block, sweat-proof, and baby-block sunscreens if spending extended periods in the sun. The petroleum bases in these products can cause the skin to overheat quickly.
Take frequent shade breaks. Taking 15 minutes or more per hour is enough time to let your skin cool down and recover.
Never expose burned skin to more sun. Burned skin will not tan—it will only get worse. Keep burned skin cool and try to minimize sweating to reduce chances of blistering. Never put waterproof sunscreens on pink or burned skin, as it will overheat.
Healthy sun protocol: Whether it is the start of a summer trip or a visit to a sunnier locale, allow your skin to slowly get accustomed to increased levels of sun. Start with a short amount of time in the sun (less then 15 minutes at a time). Once you work up to an hour, take a shade break. Gradually progress to longer sun exposure. Having an established base tan means that your skin is producing enough melanin to supplement the protection of the sunscreen you are using. As you develop a healthy tan, you can use a lower SPF, letting your skin absorb healthy amounts of vitamin D–producing UVB rays.