Also, of course, you are taking advantage of the lotion's moisturizing effect. Before your noon walk, you should reapply the sunscreen. This may be inconvenient, but it's a must if you are relying on it for protection. The only real alternative is to wear a broad brimmed hat, which is a good idea, sunscreen or not. Also, don't forget to cover your arms and shoulders either with a sunscreen or clothing.
Sunblocks contain zinc oxide, titanium dioxide, kaolin, talc or iron oxide.
And they are opaque, like the white stuff lifeguards put on their noses. Because sunblocks reflect all the UVR, they do not carry an SPF rating. The disadvantages of these products are that they wash off easily, and they are messy and sticky. Some cosmetics and sunscreens, including Oil of Olay, now have added a reformulated, clear sunblock to their sunscreen lotions to provide more protection. Check the labels.