Therefore, a good pair of sunglasses do not have to break the bank. Lips are particularly vulnerable to the harmful effects of the sun because lips lack melatonin, the skin's natural shield against the sun. Sunscreens work by filtering out harmful UV rays. The higher the SPF the greater the protection, depending on many factors including individual skin type, how the lotion is applied, sweating and swimming. When the sunscreen is applied is also important.
Warm skin absorbs .the lotion differently and heat causes a chemical change in the sunscreen itself.
If sunscreen is applied just before you jump into your kayak instead of on your cool, dry skin first thing in the morning you can effectively reduce the protection factor by half. Sunscreen also tends to roll right off of wet skin instead of being absorbed so make sure that your skin is dry when re-applying throughout the day. Sunblock provides a thin layer of opaque grease such as zinc oxide, talc or titanium dioxide that literally blocks out the sun's rays. These products are especially good for nose, lips and people with fair skin. Both sunscreens and sunblocks should be used in conjunction with hats, sunglasses and protective clothing.