How long can our body be exposed to UV to not cause health problems like skin cancer, etc,. In some parts of the USA, the UV index can reach High (7-9). I'm trying to understand if I need to stay outdoors during this time for few hours, can it cause skin cancer? If not, how long is the safe duration without having health issues?

1 Answer 1


Any amount of time in the sun is enough to give you skin cancer. Sunscreen should be used frequently during these times..or whenever you go out in general. One common misconception people usually have with sunscreen is the duration and strength of the sunscreen. SPF (Whatever the number is) does not indicate how strong the sunblock is..SPF- Sun Protection Factor is the amount of time you have until it wears off. So, if you have a sunscreen at SPF 15, you'd best be reapplying it every 15 minutes. In high UV index, its best to avoid the sun, but if you must go outside, I'd recommend covering most of your body and applying sunscreen.

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    your explanation of SPF is wrong. SPF 15 does not mean it will last 15 minutes. It means it will take 15 times as long to get a sunburn. I can get a sunburn from 10 minutes of exposure: SPF15 means I will get one after 2.5 hrs. I will get damage to some extent if I am out for less than that time. I personally wear 100+ when I am out. All sunscreens wear off, especially if you're sweating, rubbing yourself with a towel etc, and should be reapplied every hour or two regardless of their strength. Aug 21, 2017 at 18:49

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