- Skin, will one application of sunscreen be okay for the whole day? - It’ll be fine for you. - How come? - Well the UV index in our town is rarely above 3 so you should be safe even without sunscreen. - But what about the days when UV is above 3? - One application in the morning will be enough for you since you’re not outside for more than 2 hours. - But why do people say that you should top it up throughout the day? - It’s for people who are out in the sun for more than 2 hours a day. - What will happen if we don’t reapply the protection? - Imagine that sunscreen contains little protectors. Half of them will get so tired protecting you for 2 hours they will just pass out but the other half you’ll rub off with your hands or clothes. - Aha, so it turns out we really do need a new portion of protectors. - Yes. Without them we are likely to get pigmentation. And then people wonder - ‘Oh but I always put sunscreen on but keep getting pigmentation spots!’. But thats because protectors can’t work forever, but only for 2 hours as is stated on the packaging. - But why do some people insist that the previous layer of sunscreen should be washed off before we apply a new one? - Because there is also the third group of protectors. They can still work for 2 hours but if you leave them for longer.. they go crazy and start attacking all the surrounding cells. - Ugh! - Dont worry! Just follow the 2 hour rule and you’ll be fine!