I don’t know about you, but I went through a phase of hating it when I had to put on sunscreen.

Even though I’m past that and  now way too into skin care and I know the smell and  sticky sensation is worth it. It’s tempting to believe  the rumors that weird things like Aspirin or clouds can make a sunburn worse.

Good thing that researchers have put those claims to the test and are telling us which  circumstances really do lead to nasty burns. Not to mention other even  gnarlier stuff like melanoma. So here are the conditions that will  give you the worst sunburn of your life. [♪ INTRO] This might seem totally  unrelated to UV protection, but some of those over-the-counter  drugs you take for a headache might be contributing to your sunburned skin.

NSAIDs, or Nonsteroidal Anti-Inflammatory  Drugs, like ibuprofen or aspirin, can help you with all sorts of  discomforts from inflammation to fever. But while they’re great for helping  you feel better in those ways, a lot of experts say that some NSAIDs  can increase your risk of sunburn. They can increase your photosensitivity, basically lowering the  threshold for how much sunlight you’re exposed to before your body reacts to it.

Some drugs are activated by UV  light, creating super reactive forms of molecules like oxygen in your body  that can damage your skin like a sunburn. So it’s important to be extra  good about wearing sunscreen when you have a headache, if you’re  gonna take something for that. But if your headache happens after you’ve been out in the sun and you want some  meds, there’s good news for you.

Other research has shown that taking NSAIDs mainly after sun exposure can help  decrease how bad a sunburn gets. Your average sunburn happens  when your skin absorbs UV rays, triggering your immune system to  react and causing inflammation. Then, NSAIDs like aspirin and ibuprofen can do their typical work by reducing  inflammation, even from a sunburn.

And a side note, but totally  related because sunburn and melanoma go hand in hand: aspirin  can fight against skin cancers. Melanomas, like many other cancers,  are most dangerous when they spread. And aspirin reacts with a chemical  in cancerous melanoma cells to form super-reactive oxygen that helps  stop those cells from spreading.

It’s like NSAIDs can be  pro-sunburn before you go outside and then anti-sunburn and  -melanoma after the fact. Make up your mind! But NSAIDs aren’t the only thing that get more or less risky depending on your sun exposure.

Water can do that too. If you think being underwater keeps  you safe from sunburns, think again. Since water is see-through.  It’s also… sun-through?

So it’s not an impenetrable  forcefield against the sun. That said, it can reduce the  impact of the sun’s rays. The deeper into the water you  go, the more protection you get.

And when waves are making foam, a  lot of plankton are swimming around, or other factors are making the water  more opaque, less UV gets through. If you go 2.6 meters, under turbid  waters, you’re almost fully protected. But if it’s clear water,  you might need to be around 9 meters under to get the same protection.

But that’s not how most people  spend time in the water. You’re more likely to be waist deep, splashing around and throwing  a football or something. And under those circumstances, the water  can reflect the UV rays back up at you.

We’ll talk more about  reflective surfaces in a minute, but for now, just know that that’s a risk. So your best bet is probably to go  scuba diving many meters underwater, hang out in gross murky water, or  maybe just wear some sunscreen. In fact, you should be wearing sunscreen even when you don’t think you need it.

Like when you’re sitting in the shade. When you’re on a really hot  walk, finding a shady tree to sit under can feel like  the best thing in the world. And while it might help you cool  off, chances are that that shade isn’t giving you as much protection  from the sun as you might think.

Shade is deceptive. There’s no standard amount of  shade that counts as shady, and some trees are better than others  for protecting you from the sun. Researchers led a whole investigation to  figure out which trees are the shadiest.

And they concluded that in Queensland, Australia, the best shade protection comes from  the Ficus beghalensis banyan tree, which has branches that spread  horizontally with a lot of coverage. The worst protection comes  from the Alexandra Palm, which stays pretty vertical and sparse. But even the banyan tree only covers  67% of the sky if you’re right under it.

It’s not enough to protect you from sunburn. So don’t rely on tree shade as  your only form of UV protection. Even shade from clouds totally obscuring the sun can’t be trusted to completely  defend you against solar radiation.

According to the World Health Organization,  thin clouds can scatter sunlight, which might make it more dangerous  than having no clouds at all. But a thick cloud cover can offer  a bit of shelter from the UV rays. The point is, in the shade you might  end up with a false sense of security that increases your risk of sunburn.

Like if you’re in the shade of a tall  building but there’s open sky above you, those UV rays are still hitting  your poor exposed shoulders. Even if you’re in the shade of a built  structure like a ledge or fabric sail, sun protection depends on how much of the sky peeks through it and how reflective  the surrounding surfaces are. Speaking of which…This  might sound straightforward, but if you’re standing next to a steel building, the sun can reflect off it  and onto you even though you’re under the solid cover of shade.

Being near a shiny, smooth surface can increase your UV exposure by an average of 20%. But not all metallic surfaces  come with the same risk. One study found that a pale green metal  surface won’t increase your UV exposure as much as the silver shiny  building materials we see the most.

Or at least the green option was  better at most hours of the day. Around noon, there’s just too much  sun for it to matter that much. So maybe we should be stepping up city aesthetics for more  reasons than just tourism!

But there are other reflective  surfaces you might not be thinking of. Sand, concrete, and other types of  light-colored ground are reflective. You can end up catching an  extra 15% of the sun’s rays just by standing on a beach.

And even when it’s cold out,  reflective surfaces are gonna reflect. That’s why skiers sometimes get  an atrocious goggle sunburn – because snow is super reflective. Like up to 90% reflective!

So don’t let temperature fool you. Sun is sun, and it can burn  you even when it’s cold out. Except, the sun doesn’t always hit the same.

But before we get into that, here’s a quick ad. Since you watch SciShow, I  know you’re the kind of person who loves engaging with new ideas  and learning outside of a classroom. And that’s what makes this video’s  sponsor, Brilliant, so great too.

Brilliant is an online learning platform  made for everyone from age 10 to 110. And in the years that they  have sponsored SciShow videos, they’ve continued to come out with new, topical courses that strengthen your math  skills, improve your confidence in coding, and excel in data, science, logic, and more. For example, like their course on How AI Works!

To learn for free on Brilliant for a full  30 days, go to brilliant.org/scishow, scan the QR code onscreen, or click  on the link in the description. Brilliant’s also given our viewers 20%  off an annual Premium subscription, which gives you unlimited daily  access to everything on Brilliant. Throughout the day, the angle of the  sunlight changes as the earth rotates.

Depending on where you live, if you go outside around noon,  the sun is right above you. And that means your UV exposure  is more direct since those rays have to spend less time and distance  travelling through the atmosphere to hit you. But in the early morning or late afternoon, the sun’s rays pass through the  atmosphere at a totally different angle.

So the atmosphere has more time and distance to absorb UV radiation before it hits you. Now, the sun’s angle also  changes throughout the year. And if you go outside in the summer, you can get 4-6 times more  exposure than in the winter.

And since this is constantly changing,  the extra UV can take you by surprise. Kind of like what happens at high altitudes. High altitudes are risky mainly because of ozone, but also because of the amount of atmosphere that UV rays go through before they get to you.

There’s just less of it up there  to absorb the UV radiation. And regardless of the sun’s angle, there are fewer air molecules to scatter  the radiation for you at elevation. In fact, for every 1000 meters that you climb, the UV intensity increases by about 10%.

So a high altitude can kick  your butt on multiple levels. It’s not just harder to breathe and dehydrating. The sun is also more likely to burn  you and damage your skin up there too.

Which is why living in the  mountains poses certain risks. Particularly if those mountains  happen to be near the Equator! How far you are from the equator can  affect how likely you are to get sunburned, and it all comes back to angle and atmosphere.

The sun varies where it is directly centered over, but for the most part, it’s the equator. So if you’re close to the  equator, the UV is higher because the sun’s rays travel a shorter  distance through the atmosphere. The equator is like the “noon”  of locations for UV exposure.

Plus, the type of atmosphere that is  really good at absorbing certain UV rays, which you might know as the ozone,  is just naturally thinner there. So you might assume that  the highest melanoma rates in the world are found right on the equator. But you’d be wrong!

That honor goes to Australia and New Zealand. A little South of the equator. They’re at high risk for skin cancer  and sunburn for a couple reasons.

One of those reasons is not that Australia  is under like a full-on ozone hole. This is a common misconception. What might have contributed to the  misconception is the historically lower amounts of ozone in the  Southern Hemisphere during the summer compared to the Northern Hemisphere.

But it isn’t as big of a deal as an ozone hole. And, yes, there is an ozone hole  above Antarctica for part of the year. But it doesn’t really extend over  to an area where people live… unless you’re like a really  cool scientist studying there.

What’s more likely to affect  Australia and New Zealand is Earth’s wonky elliptical orbit. When the Earth is tilted so that the  Southern Hemisphere points toward the sun, AKA summer time, Australia is 5  million kilometers closer to the sun than when us Northern Hemisphere  folks experience summer. That makes some researchers  estimate that the UV is up to 30% more intense than comparable  Northern Latitudes during the summer.

On top of that, New Zealand  and Australia are doing pretty well on keeping their  air pollution levels down. Which is great! But it does mean that  there’s less stuff in the sky to block those strong rays from  hitting people on the ground.

So being close to the equator is a factor, but also being south of  the equator sometimes means you really need to reapply that sunscreen! And all of this means the worst sunburn  of your life would probably happen in Australia, during the summer  around noon, on top of a mountain, waist-deep in clear water,  surrounded by shiny buildings. If that’s where you’re watching this video from, do yourself a favor and remember your sunscreen. [♪ OUTRO]