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13

All sunscreens are physical barriers, designed to absorb or reflect UV radiation. They rub off over time, and they will rub off faster when exposed to water/moisture, most commonly from sweating or swimming. Friction (e.g. from towel-drying) also removes sunscreen. Some chemical sunscreens do break down when exposed to sunlight and require the addition of ...


12

Around sunrise and sunset, the sun is much less intense. You would get around 5 times less intensity in the first or last hour of sunlight than in the middle of the day. Here is a graph of this effect (It's from a paper, though the paper itself is behind a paywall), and another one which also shows the effect of latitude. Therefore, while you can’t say ...


10

As it is stated in this Wikipedia article, the sun protection factor (SPF) roughly describes how the time that your skin is able to protect itself from sunburn is elongated. To take the Wikipedia example: if a person develops a sunburn in 10 minutes when not wearing a sunblock, the same person will prevent sunburn for 150 minutes if he/she wears a ...


8

I'd like to add to the existing answer that while sunscreen effectiveness does decrease as it is absorbed into the body, wears off, or is washed off, high SPF sunscreens will still block most sun after the two hours. The FDA recommendations for reapplication every two hours are basically to provide maximum protection, because the level of protection does ...


8

As found here: "With every 1000 m in altitude, UV levels increase by approximately 10 per cent." Percentages are tricky to work with, so here is a worked-out example. Suppose you start out at sea level (0m), and you climb all the way up to Mt. Everest's summit (8848m). Suppose also that at sealevel, you normally need to apply sun block factor 15. Then, ...


7

Polarized sunglasses, as with other type of sunglasses may not block enough UV to be considered safe. From WikiPedia: for adequate protection, experts recommend sunglasses that reflect or filter out 99-100% of UVA and UVB light, with wavelengths up to 400 nm. Sunglasses which meet this requirement are often labeled as "UV400. In other words, ...


6

Heat illnesses are about heat, not light, and while the two are not unrelated, the hue of your clothing would be a very minor factor— red would not provide better or worse protection than green or blue or any other part of the visible spectrum. The shade may have some impact: since darker clothing absorbs more energy than lighter clothing, it warms up and ...


6

If you absolutely must have a fire, reset your thinking from "fire pit" to "fire mound" Creating a fire mound is a great way to enjoy a back-country fire with little to no impact to the ground / vegetation. Carry a small sheet of plastic, burlap, or a section of an old fire shelter, or anything of the like (it shouldn't get hot enough to burn if your ...


5

Your mileage may vary, so know thyself. Start conservative, it is easier to back-off on protection than it is to treat sunburns. SPF 50 is not too high and you may want an even higher SPF when starting. Sunscreen that contains titanium dioxide or zinc oxide is great because they protect against both UVA and UVB. Since they are also inorganic compounds ...


4

Polarization and UV protection on sunglasses are two different things. While UV refers to light of a wavelength of approximately 10nm to 400nm, light of any wavelength can be polarized. So polarized sunglasses do not generally protect against UV, they also need a dedicated UV filter. Light emitted by the sun oscillates in all directions perpendicular to the ...


4

You don't need a trad rack of your own in order to follow. If you're climbing with experienced trad leaders who have their own racks, then you also don't need to bring your own rack. If you're going to lead, you just borrow their gear. In your situation, there is really no advantage to buying a lot of trad gear before you try following on trad climbs at all. ...


3

A skin is a skin, so there's no difference if you take off your T-Shirt or your pants first time in the season. The less the body part is used to the sun, the more protection it needs. Well, the only difference is the skin on the penis, which is usually naturally a bit darker, so it already has more sun protection (which doesn't mean you can't get sunburns ...


3

Well, insulating the floor from a campfire, which usually has 900-1200 degrees Celsius and burns for several hours, is quite difficult. The soil itself does a decent job, but of course that's the part that you don't want to burn... Restoring life to a scorched patch of soil will take a while, but relatively speaking a couple of scorched patches won't make ...


3

Go to your nearest builder's supermarket, or even check a normal one, and look for worker's gloves. Or mechanic's gloves. Such as are used by people building houses or repairing cars. Those are very resistant and cheap. I've bought my ones for about 2-3$ (price in Poland, but I've found similar gloves in Germany too, only it was a small craftsman's shop). ...


2

A white colour for head protection (and all other clothes) will keep you the coolest, black will keep you the hottest. All other colours are somewhere in between. This is because white fabric reflects the most light (all wavelengths of visible light), while black absorbs all (red reflects only the red channel). As for the efficiency - I have sometimes ...


2

I can't help but think that this question may trolling, but here goes anyway. There is a difference between skin and skin if one includes the glans as it is mucous membrane: anything marked "for external use only" might cause unexpected irritation. Don's humorous remark about capsaicin is a good example that I'm sure more than a few men are accidentally ...


2

One thing I think that's missing from Ben's answer is a half rope. If your climbing on a trad route that moves about a lot you'll want to use two half ropes rather than a standard single rope. The idea behind a half/double rope is that it reduces drag, if you have two anchors that are far apart on the same route, this can produce a Z in the rope which ...


2

You could look at sailing gloves such as these. There are loads of different varieties with open or closed finger versions depending on your preference. As mentioned by others many sailors also use rubber gardening or builders gloves. These are much cheaper but wear out a lot faster. I'm not sure how much of an issue this would be for kayaking.


1

I use these regularly for Kajaking, since i nearly ripped off my flesh while getting out of my yak at a stonewall. They're not waterproof, but they're very durable in my opinion and they dry very quick, and as an extra they are windproof. And also the seams don't rip at your fingernails while paddling as many others did which i tried. The palms are made out ...


1

There's two schools of thought here that I know of - the first is to avoid lighting a fire where there's ground you could easily damage, and the second is avoiding the heat getting to the ground. Combine both if you can. As far as the first goes, I won't say a great deal about that because beyond the obvious (being open minded about where you camp and ...


1

If you are looking for a cooking system for backpacking the Caldera Sidewinder Ti-Tri have the option of using a titanium floor for this exact purpose. In the interest of facilitating Leave No Trace wood burning practices, Trail Designs offers two styles of titanium floor plates to go under your Ti-Tri systems. The "split floor" is designed to go with ...



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