Having healthy skin doesn't mean you should never go out in the sun, it just means you need to be responsible and protect your skin when you do. Many people still don't properly understand the damaging effects the sun has on your skin (even on a cloudy day!). Therefore it is vital that before leaving the house every morning, put on a moisturiser that contains an SPF of at least 25. Stay out of the midday sun (from 10 in the morning to 4 in the afternoon), which is the strongest sunlight.
Find shade if you need to be outdoors. You can also calculate how much ultraviolet (UV) exposure you are getting by using the shadow rule: A shadow that is longer than you are means UV exposure is low; a shadow that is shorter than you are means the UV exposure is high. Apply sunscreen to all the skin that will be exposed to the sun, including the nose, ears, neck, scalp, and lips. Sunscreen needs to be applied evenly over the skin and in the amount recommended on the label.
Most sunscreens are not completely effective because they are not applied correctly. It usually takes about 1 fl oz (30 mL) to cover an adult's body. Apply sunscreen every 2 to 3 hours while in the sun and after swimming or sweating a lot. The SPF value decreases if a person sweats heavily or is in water, because water on the skin reduces the amount of protection the sunscreen provides. Sunscreen effectiveness is also affected by the wind, humidity, and altitude.
