I am soon going to visit Las Vegas, and I heard that high temperatures are very normal there. I can't rule out the possibility of taking a walk while it's, say, 39 degrees Celcius. What steps can I take to make this more comfortable? I heard of hydrating, covering the head and wearing appropriate (lightweight and not dark?) clothing, but what else is there to keep myself comfortable?
Vegas is a dry heat--while this is often scorned by those who don't understand the difference it means that your body can do a much better job of cooling itself than you might expect. Your body sweats, it very quickly evaporates and you are nowhere near as aware of the heat as you would think.
As others have said, bring plenty to drink--although since you say you aren't going to leave the city you also can travel light and buy stuff along the way.
If you do leave the city tell someone where you are going and when you're going to be back. If something happens you need search and rescue to be out there promptly. Note that if you're outside the ring of mountains around the city that cell phones will be iffy.
I would also recommend sunscreen. The summer sun here is brutal.
You may want to look into buying clothing specifically marketed as keeping you cool. I regularly ride my bike 15 km in 30 C heat. In a white cotton tshirt, sweat runs down my arms and I have trouble gripping the handlebars. In a long sleeved "performance " shirt I feel much cooler (even in a dark blue one) and sweat far less. I also drink less water in those shirts. Example: http://www.mec.ca/product/5032-035/mec-rhythm-long-sleeve-womens - I have no affiliation, I own three of that shirt though.
A long sleeved loose shirt, even if it's not a special cooling shirt, may well be cooler than bare skin and will protect against sunburn. You may also be glad of it when you go inside and the air conditioning is on stun.
I'm resident in Canada and occasionally travel to Dubai to visit my parents. I am in Dubai right now and it was 44 degrees Celsius this afternoon. Note that I am used to wearing shorts even when it is lower than 0 Celsius while in Canada.
Here is what I have for you:
We are Vegas locals, and love hiking.
If you are going to hike in the hills, take tons of fluids. More than you think. Only because running out, cuts the fun short.
Consider a hike in Mt Charleston. 20-30 degrees F cooler than downtown.
Also consider hiking in Red Rock Ice Box Canyon (hint, hint -- the name).
We like to trail run in the evening, after 6pm. As soon as the sun's off a little, the temp drops. By far my favorite is trail running at night (headlamp). The trails are easy to follow, it's an amazing experience, cooler, and feels like an adventure.
The heat is a dry heat, so it's not the heat that's a problem it's the sun. So if it's an overcast day, it's actually not so bad.
Also the part of town. The hottest is downtown (concrete), and Henderson (oven). Summerlin and towards Red Rock is the coolest. In the shade or early evening, quite pleasant.
The hiking, rock climbing is world class here. Once you leave the strip, it's quite amazing, and tons of groups. There are at least 4-6 hiking meetup groups. Each with 200+ members. There are literally 3-4 organized hikes per day going out, all inside the city, and they know where and when to go to be coolest. So get on meetup before you go, join and tag onto one of the groups. Some of the leaders take you into unexplored areas, other leaders more standard fare. But lots of options, lots of fun.
If you can find a shuttle to Mt Charleston (or rent a car) you won't be disappointed, bring a jacket (you will get cold), 2000+ year old trees, views, etc, etc.
But your best bet is meetup, those hikes tell you exactly what to bring (how much water, jacket if required, etc).
Don't think you can walk at your normal pace when it's much hotter than you're used to. Take it easy and allow longer than you think it'll take to walk anywhere. Force yourself to walk more slowly any time you catch yourself going quickly.
Hydrate and cover your head, yes. Lightweight clothing, yes within reason but not gossamer see-through stuff. Colour is less of a big deal than you might expect but all else being equal you'll be a bit warmer in darker clothing, so avoid it.
karancan already mentions sunscreen. I find that sunburn is orders of magnitude more uncomfortable than just missing out on the (anyway debatable) cooling effect of showing a bit more skin. As such I treat it as the primary issue above all others.
That's why I prefer long-sleeved and long-trousered clothing. Loose-fitting clothing with a tight-weaved fabric has its own cooling effect anyway since it keeps the sunlight off most of your skin. I may be stereotyping, but for a Slav moving 15-20 degrees of latitude south near mid summer, "significant amount of time" exposed to sunlight is, like, a minute. If you can feel the heat of the sun on you, get sunscreen immediately onto anything that sticks out. Don't forget the hands and the hairline at your ears and neck.
Beware that sunscreen can be rather unreliable if you're sweating a lot or pour water on yourself. Consider waterproof kinds if this becomes an issue. If you have fair skin (and possibly even if you don't) you might as well get the highest factor you can find (if it's not 50 something's wrong) and re-apply according to the directions. Hug the shade, especially initially until you get a feel for even what a few minutes of sun feels like.
Next worst thing after sunburn is exhaustion and sun/heatstroke. Drinking water, hat, dark glasses. Pay attention to your breathing and how your head feels (dizziness or headache is bad, get out of the sun). Expect to walk slowly, drink frequently in small amounts, a bit more than you think you need. Beware drinking very cold water: it messes with your subjective expectations and might make you feel less thirsty than you "should" be.
Pay attention as you go, how much difference the time of day makes. Even if the "officially measured" air temperatures are similar, there's a huge difference between going for a walk at mid-day or late afternoon.
Somewhere down the priority list is how hot you actually feel. In 39 degrees you're never going to feel chilled, especially walking around sun-heated city streets, so to some extent you should just accept you'll feel uncomfortable and concentrate on avoiding anything that will make you feel really uncomfortable (getting burned, vomiting through over-exertion, hyper-ventilating, passing out, that kind of thing).
That said, if you find that you personally feel most comfortable and reasonably cool walking around in the sun in close to no clothes, then sunscreen up and get on with it. Just mind the dress code of wherever you're going! A couple of pairs of shorts doesn't take much packing space in addition to clothing that will cover you, so you can keep your options open.
Doing what the locals do has its merits, but in Las Vegas a lot of the apparent "locals" (a) don't know what they're doing, they're actually visitors just like you, and (b) are kind of pink-looking. So you should only trust what you see around you so far.
Many others have mentioned the clothing, especially the color. I am also of the long-sleeved fraction, but! I don't think that sports clothing is your best bet. It is made from synthetics, and they cause a bit of greenhouse effect and don't wick sweat that well, despite the manufacturers' promises.
In the really high heat, it's best to wear linen. It has a nice cooling effect. I think ramie will work well too, but have never had pure ramie clothing. Silk can also be quite good, but it's hard to find silk substantial enough to not be transparent without matching the price of your plane ticket. The athletic synthetics come in next, and only after that come thin wools (also rare and expensive), then cotton and kapok (cotton is absolutely terrible in conjunction with sweat), and last of all are everyday synthetics. Loose cuts and light colors are good too. Avoid layers - in a casual situation, it might even be better to go commando under dark colored pants than to wear light pants over underwear.
For the head, don't forget enough shade. Don't just wear sunscreen, you should also be concerned about the visible light entering your eyes and causing all kinds of physiological mayhem beside the unpleasantness of feeling blinded. Make sure you have very dark glasses (category 3 at least, better 4), and a broad-brimmed hat. If you need vision correction (especially if you are myopic, which frequently causes photosensitivity), make sure you don't have to choose between seeing stuff (wearing regular glasses) and feeling OK but going half blind with sunglasses without correction.
Finally, if you absolutely can't stand the heat, here is a trick to use. You need to cool rapidly your blood. This is best done with constant wetness at a place where a major blood vessel comes very near to the skin. The most convenient place is the wrist, where you can measure the pulse. You can even wear sweatbands and keep wetting them. If you don't have a sweatband, but notice the early heat stroke symptoms, use a paper tissue. Wet it copiously and wrap it around the wrist, it will stick there by itself. When it starts peeling off, it's too dry, wet it again.
There is a corresponding point at the ankle, but it is not so convenient to keep wet, and the femoral artery in the inguinal area is an even worse target, and the area is probably already sweating enough anyway. But the other options are prime candidates: the carotid artery and the blood vessels at the temples. The carotid becomes especially important if you are already having a mild heat stroke, because it goes straight into the brain.
It's a good thing to try to pay more attention to your body before you start the journey, so you can tell easier when there is something amiss. Ask yourself explicitly how you feel - tired, hot, etc. - to make yourself a bit more vigilant, and also to learn better what's your usual state. Also try learning to recognize dehydration early - for example, I can dehydrate enough for my lips to chap before I feel thirsty. Once you have done this, you'll be better equipped to recognize potential problems and nip them in the bud using the obvious methods (go inside a climatized building, drink, etc.).
Stay away from being outside for a long period of time when it's hot outside. If you want to explore the city, it might be best to set out early (7:30 AM latest) or in the late evening. From about 11AM-4PM is the warmest time of the day, so try to stay out of the heat then.
I live in the USA where temps range from about 105 to -10 degrees F during the year, and you get used to it. I've had to go outside for gym classes before in the heat in the middle of the afternoon, but it's bearable. Just make sure that you have lots of water. Keep in mind that you should drink hours before AND after you go outside. I often have a water bottle by my computer (where I go after I get home) that is about 3 cups and I drink most of that that within 20-25 minutes or so and fill it back up to keep drinking (at a much slower rate... like pointed out, if you drink too much, it can be unhealthy).
Remember, dark clothing is dark because it turns all the light into heat. White clothing is the best. Lightweight clothing is nice, but there is another grade of material that's specifically designed for athletics. If you want to try that out, give it a shot. I generally like wearing that material anyway around the house because it's quite comfortable.
If you're feeling lightheaded/showing other symptoms of dehydration, it's best to go into a building somewhere that has AC and cool down, drinking lots of water. Other choices of drink usually negativity affect your hydration levels, so stay away from pretty much anything except pure water. I like adding ice in an insulated water bottle to keep it nice and cool. Note: "Smart Water" isn't usually good since is seems to have no salt in it (unlike most natural water), so you won't have any salt to sweat out...
The last thing I can think of is educate yourself on how to be safe with hot temps. Make sure not to push yourself too hard if you're not used to the heat.
Stay hydrated. Be sure to drink lots of liquids, especially water.
I agree with all the other answerers about clothing and water. A simple way to cool down is to wear wet clothing. So, you bring extra water with you and keep your clothes wet by spraying it on your clothes. The more water you can evaporate off your clothes this way, the less water you lose in the form of sweat. The advice given by Bear Grylls in an episode of "Extreme Survival" on Discovery channel is to use urine to make your clothes wet as that saves precious drinking water, but I don't think lack of water will be a problem in this case.
You need to bring enough food with you. Eating enough will also help to prevent water poisoning.
You need to pack warm clothes, in the evening temperatures may go down fast.
In addition to all the previous answer, I am often shocked to realize how many people don't understand how to use a fan.
I heard many people saying it is useless if it blows warm air. That is, of course, 100% wrong.
So, as long as you are in a closed room with no ventilation, it doesn't matter much if you wear long of short clothing. But as soon as there is a gasp of wind, GET NAKED! With sun block if needed.
In desperate situation, get soaked wet. Even better if you wear long clothing. If there is absolutely no wind to evaporate all that water, just walk to generate that precious breeze. If you walk in the desert and regularly pour water on your head and your clothe, you are more likely to get a cold than a heat stroke
Wear white clothing. Wet a towel or a cloth with water and put it over your head and put a hat or cap over your head.
protected by mindcorrosive♦ Jul 28 '14 at 6:55
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