
Eight low-tech ways to keep cool in a heatwave (2013) - vanilla-almond
https://www.bbc.co.uk/news/magazine-23255554
======
Panino
> Lukewarm showers

I think this is personal. Ice cold showers help me immensely and consistently
in multiple climates. My wife (originally from another country) prefers to
take hot showers. Although that sounds awful, if I feel her skin afterward,
it's cool to the touch, so I know it works for her. So I of course tried it
and it was a nightmare. Never again.

Where I live it was 40C/105F yesterday and we don't have air conditioning.
It's actually not bad when you have a strategy in place. In college I lived on
the 10th floor of concrete building that also lacked air conditioning. I think
the list in this article is good mainly for short term relief. It's also
optimized for situations that aren't very applicable to most of its readers.

In France, it's standard for windows to have white exterior shutters that both
repel sunlight and prevent it from entering a home through the window. They
are controlled easily from a handle indoors next to the window. This should be
standard in homes and buildings worldwide. If you prevent heat from entering
in the first place then you can greatly reduce the "need" to use air
conditioning. I can personally attest to how effective they are.

Simply opening the windows at night helps a lot since where we live it gets
cool enough. Whole house fans (run in the early morning or late evening),
ceiling fans, and cool drinks are enough to keep me comfortable indoors no
matter the temperature.

~~~
CompelTechnic
I often wonder why nobody paints their roof white. I see all this black
asphalt soaking up heat on roofs in the south and think that everyone must be
crazy.

~~~
orev
It is crazy. But houses with dark roofs look better, so they sell better. And
replacing a roof is very expensive, so no one is going to do that on a new
house just for the heat. Further, many new construction houses are in HoA
neighborhoods, and HoAs don’t like people to be unique because it “spoils” the
uniform look and “decreases” property values. It’s the system working against
us. The only solution would be to codify requirements in building codes.

~~~
woofyman
White roofs stain and get dirty. Especially if leaves get on them.

~~~
orev
Lighter colors, even if not white, would still reduce absorption and increase
reflection. A middle-gray would help, and possibly something with a color tint
to it.

------
goda90
A lot of these techniques lose effectiveness at higher humidity. Eventually
water and sweat evaporation can't keep up and you're just moist and hot
instead of hot.

~~~
tootie
NYC was pretty brutal today. 35C/99F and high humidity. Shade has no effect.
The thing that works for me is to walk slow and think cool thoughts.

------
barking
“If you are cold, tea will warm you; if you are too heated, it will cool you;
If you are depressed, it will cheer you; If you are excited, it will calm
you.” \--Gladstone

------
vanderZwan
If you prevent heat from entering your house, you don't have to get rid of it
either.

The last two days I hung up two wet towels as "curtains" on the outside of
(open, curtainless) window in the living room, which face the sun during the
day. They blocked the sun, and air coming into the house through the window
was notably colder.

They dried out so quickly that I had to soak them again twice during the day.
Given how much energy it takes to evaporate all that water I think that little
hack got rid of a _lot_ of heat.

~~~
nategri
It looks terrible-slash-suspicious but I've found covering windows with
aluminum foil to be an effective technique. It's cheap, reflective, and
optically thick.

~~~
vanderZwan
Yeah, that would work even better at deflecting heat - there's a reason
chemists and physicists use simple aluminium foil as make-shift insulators
(might also block some the neighbour's WiFi signal, boosting the reception of
your own, but that's a bit of a tin-foil hypothesis :P).

You'd miss on the evaporation cooling though. Maybe a two-layer approach would
work best of all low-tech hacks! :)

In the past, when I was living in an apartment with a wider windowsill, I used
to put a reflector made from cardboard covered with aluminium foil on the
inside and sun-hungry plants inbetween, creating a miniature greenhouse. Open
windows were a requirement of course, because it would still trap heat
otherwise.

------
MrBuddyCasino
Or you could be cool like whitequark and install an industrial AC for ~100$
with All The Watts:
[https://twitter.com/whitequark/status/1010824530145759232?s=...](https://twitter.com/whitequark/status/1010824530145759232?s=21)

~~~
chrismartin
"All the watts"? Just because a fancoil can dissipate 45 kW doesn't mean there
aren't limitations elsewhere in the system (e.g. the compressor can only pump
that much coolant around). The Twitter thread mentions nothing about the
compressor..

------
bungie4
It was my undertanding that the Bedouin wore full body clothes to SLOW
evaporation. In the desert, your sweat evaporates to fast (because of the near
0 ambient humidity) not giving it enough time to pull heat out of your body.
Thus, making you even hotter.

I've experienced this very thing riding a motorcycle through Arizona. Man, it
takes some real willpower, but gearing up is what is required when the temps
go over about 85F. Just don't stop!

Tip. On a motorcycle, wet your shirt. Zip up your coat. Unzip your wrist
cuffs. This slows down the airflow giving time for the water to evaporate and
cool you, while providing an intake and exhaust. You will be amazed at how
well this works. You can actually regulate the temperature (air flow) by
opening or closing the zipper by your neck.

This will not work in areas with high humidity like the deep south.

~~~
s0rce
Yes, while hiking in dry hot climates I wear long sleeves and long pants,
partly to keep the sun off but it also improves your water economy. Less water
will be lost and you don't need to drink as much.

------
izzydata
It's been about 95f-100f in Kansas lately and my AC unit has been dead. I've
resorted to keeping my tub full and taking a dip every half hour and letting
myself air dry.

I also haven't worn clothes at home for awhile.

------
ProfessorLayton
Also: Add attic insulation, which is surprisingly uncommon in older Bay Area
houses! Adding insulation is particularly cheap compared to the actual cost of
the house, and is something one doesn’t necessarily need to hire a contractor
for.

~~~
rconti
Our bay area home has tremendous southern exposure. Thankfully the attic is
insulated, but I really wish we had gables so it would be easier to install a
whole house fan. The house itself rarely breaks 80 but I have to use fans in
the windows to cool it off at night; I can only imagine how much cooler the
house would be if it wasn't (say) 120f in the attic.

~~~
blacksmith_tb
Solar-powered attic fans might help (the southern exposure would let them
generate plenty of power). Light-blocking shades on the outside of the south-
facing / west-facing windows likely would help, too.

------
analog31
I suppose one idea is to adjust your work hours, so your employer is keeping
you cool during the hottest part of the day. They're cooling the place anyway,
so I doubt it costs them much to have you there. And maybe cooling a bunch of
people in one place is cheaper than cooling a bunch of nearly empty houses.

In contrast, I ride my bike to work, so I start super early in the summer in
order to avoid getting drenched in sweat.

The problem here in the Midwest is that it gets cool at night, but with
virtually no wind, so we use some window fans to bring the cooler air into the
house.

------
mabbo
I was in Phoenix Arizona this week for work and was amazed at the
effectiveness of evaporation cooling. Bars and restaurants spray water mist
into the air near their front door. The air is so dry that the water
evaporates near-instantly (the ground doesn't even get wet under it!).
Evaporating water pulls heat from the air, and suddenly 42C turns into 28C.

It's simple, low-tech, and effective.

~~~
nerdwaller
Isn’t it amazing disembarking the plane into AZ? Instantly it’s 98F+ on the
jetway, and the plane absorbs a large portion of that as they ask you to close
the window shades on landing. I don’t quite understand how one can live there
if they like being outside at all. Perhaps enough months of the year make it
worth it? It is, however, a nice place to visit from a cultural standpoint.

------
AdmiralAsshat
Can anyone speak to the advice I received years ago (on move-in day at a
college dorm with no AC) that two box fans--one pointed outward and one
pointed inward--would be more effective than having them both aimed inward?
Supposedly helps create circulation, but, I'm not sure I buy it.

~~~
lozaning
If you think of your room like a rack mount server it totally makes sense.
I've never seen a server with fans pulling air in from the front AND the back,
only only ever in one side and out the other. You want to get air in, have it
absorb heat, and then get rid of it. Having positive pressure in your room or
server just results in high pressure warm air, not a cooling effect.

~~~
schiffern
>If you think of your room like a rack mount server it totally makes sense.

I'm not sure how good that analogy is. Generally a box fan is loosely fit in
the window and has an open interior with no shroud, as opposed to server fans
which are tightly mounted to a fan-sized hole and have a close-fitting shroud
around the blades. This has a big effect on the optimum configuration, because
the box fan's suboptimal design happens to be _more_ suboptimal at sucking
than blowing (while a server fan is good at both, being closer to an ideal
actuator disk)

I have observed that, in general, a box fans work better at blowing _out_ a
window than sucking _in_. At first this confused me. Why should this be the
case, given time reversal symmetry?

Here's my hypothesis. The fan produces a high velocity jet of outlet air, but
sucks in any air nearby (that's why you can _blow_ paper across the room, but
you can't _suck_ paper across the room, another seeming violation of time
symmetry). Since the fan is located nearer to the interior of the window, it
can either A) _blow_ an outward jet that maintains its momentum through the
window, or B) attempt to _suck_ an inward jet of air through the window. That
doesn't work, so it mainly intakes warm interior air, resulting in mostly in-
room recirculation with very little flow through the window and very little
static pressure created to drive whole-house airflow.

Think I'm full of shit? Good, then your skepticism is working! Don't take my
word for it. Anyone can test this using a phone with a barometer. Put the
phone on a table (for constant altitude) in the room with the fan. Compare the
pressure drop (exhaust fan on vs. off) with the pressure rise (intake fan on
vs. off). If I'm right, the absolute magnitude of the pressure _drop_ should
be greater than the pressure _rise_ , indicating greater airflow in an
exhausting configuration.

If you only have one fan, definitely have it pointed _out_ , not in. The
moving column of cold air cools the entire place, not just a single room. Also
this arrangement keeps the noisy fan in a separate room, while you enjoy the
cool air quietly wafting through a nearby open window.

I've transformed many friend's apartments from sweltering to comfortable by
implementing this tip.

TL;DR blow _out_ , not in.

~~~
lozaning
If you've got two fans though, one in and one out would be optimal no?

------
oftenwrong
>Standing under a freezing shower might sound like the quickest way to bring
your temperature down.

>But your body will react to a dramatic change like this by trying to preserve
heat.

>"If I'm hot and I go under a cold shower, I'll shut down the blood flow to
the skin and trap the heat inside me rather than let it escape," says Tipton.

>As a result, he says, it's better to use water that is in the 20s Celsius
than water that is in the 10s.

>"It's better to have a warmer shower that is cool enough to lower the deep
body temperature but is warm enough to allow the blood to the surface of the
skin."

Is there any proof of this? Even if the body makes adjustments in an attempt
to mitigate heat loss, I have doubts that these adjustments manage to make
lukewarm water more effective at cooling than near-freezing water. That seems
backwards, but maybe it is just contrary to my intuition. If 20 degree water
is more effective at cooling than 10 degree water, how does 5 degree water
compare? What if you shower in -10 degree liquid? Is 25 degree water even more
cooling than 20 degree water because it is even closer to normal body
temperature? I would like to see an experiment.

~~~
trhway
there are a lot of proof and research on this, just google and pick for your
taste. In general you want to (step 1.) transfer heat from inside the body to
the skin/lungs and (step 2.) reject it from the skin/lungs into environment.
While definitely improving step 2. the very cold water may cause blood vessels
constriction and thus significantly worsen the step 1. The same machinery is
behind the frostbites - cold environment causing blood vessels constriction
and thus lower heat delivery to the skin, toes, fingers.

On related note - reading recommendations for when for example a dog gets a
heat stroke, you will find that ice or very cold water straight onto the belly
may worsen the situation for exactly that reason. Also recommendations to in
particular cool the head - pretty straight, not that much depending on blood
vessels state, heat transfer from the brain preventing/slowing the damage.

> What if you shower in -10 degree liquid?

that takes blood flow mechanics play even further - you can get a heart attack
by quick changes in blood flow caused by the blood vessels constriction (or
quick expansion after that if you quickly get back into the warm environment -
there was that story about a ship crew rescued from cold ocean water only to
all drop dead from heart attack when they were immediately walked into a warm
room on the rescue ship). On the good note - being a Russian i like and
frequently do hot sauna until my heart can't take it anymore and jump into the
cold water (or into the snow or river ice hole back then in Russia) straight
after that - great fun enjoyed responsibly :) - the key here is having hot
sauna to really expand your vessels so they wouldn't get immediately shut down
by the cold water/ice and staying open they provide for efficient heat
transfer.

------
scotty79
I think fan on the face helps not only with feeling cooler but with actually
removing heat from the body. I read somewhere that there is a quirk in human
circulatory system that makes blood that go to the brain go through face first
to cool it down. This is probably some adaptation to long distance running. I
imagine that there might be some additional adaptation that increase
efficiency of face as a radiator.

~~~
barking
I don't think this is true. Blood to the face is supplied by branches of the
carotid arteries but all blood that goes to the face will return to the heart
then the lungs and then the heart again before going anywhere else.

~~~
scotty79
I can't find the original article but there's something about brain cooling by
the veins of the face:

[https://biology.stackexchange.com/questions/31566/how-
does-t...](https://biology.stackexchange.com/questions/31566/how-does-the-
brain-cool-itself)

Also there is some theoretical danger associated with the setup of how blood
is supplied to the brain:
[https://en.wikipedia.org/wiki/Danger_triangle_of_the_face](https://en.wikipedia.org/wiki/Danger_triangle_of_the_face)

~~~
barking
I'd never heard of this before. I had read that it is possible for infection
from the face and upper jaw to track to the the brain, so maybe there is some
venous return from the face via the brain.
[https://en.wikipedia.org/wiki/Danger_triangle_of_the_face](https://en.wikipedia.org/wiki/Danger_triangle_of_the_face)

------
wizardforhire
If the air is dry enough, swamps coolers are cheap and easy to build. I
haven’t had the chance to build a liquid desiccant system yet but it seems the
tech has advanced considerably since I last surveyed 15 years ago.

[http://www.ailr.com/liquid-desiccant/ld-
tutorial/](http://www.ailr.com/liquid-desiccant/ld-tutorial/)

[http://ashraemadison.org/downloads/Meeting_Presentations/jan...](http://ashraemadison.org/downloads/Meeting_Presentations/jan_2014_tech_presentation.pdf)

[https://www.nrel.gov/docs/fy99osti/24688.pdf](https://www.nrel.gov/docs/fy99osti/24688.pdf)

[https://www.nrel.gov/docs/fy13osti/56437-1.pdf](https://www.nrel.gov/docs/fy13osti/56437-1.pdf)

------
781
I'll add another one: put solar control film on you sun facing windows. I was
surprised by how it turned a greenhouse like room in an acceptable one - it
prevents solar heat getting into the room and making it hotter than outside.

~~~
rconti
Heh, I did this to our south-facing windows, only to realize in the peak of
summer the sun is too high and hits the roof anyway. During lower sun angle
times of year, it does help reject heat though.

------
f_allwein
Interesting approach from Munich, my home town: district cooling, i.e. using
cold water from inner city streams and distributing the cold to shops and
offices, so they don't have to use air conditioning. "produces far fewer CO2
emissions and reduces primary energy costs by around half":

[https://www.swm.de/english/m-fernwaerme/m-fernkaelte.html](https://www.swm.de/english/m-fernwaerme/m-fernkaelte.html)

------
cmarschner
Missing: green tea with nana mint, as used in Morocco. Opens the blood
vessels.

------
fmsf
Not trying to sound salty, but just for general reference. A heatwave in the
UK starts somewhere around 23C. At 20C they are already anouncing in the
stations for people to carry water at all times.

~~~
tomc1985
That's a normal day in SoCal...

one of those things I can't help but chuckle at. 73 F (23 C) is like my ideal
temperature!

~~~
freehunter
I always love the super Internet badasses from warm climates who laugh at
notherners for complaining it's too hot at "normal" temps. I'm willing to bet
SoCal doesn't hit -30. Your body is used to one small temperature range all
year, our range swings wildly and we have to cope with both extremes.

Nah, but go ahead and laugh when 80F is considered hot. We laugh in our tank
tops and shorts when you guys say 50F is cold.

~~~
sundvor
I did a crit bike race in Melbourne in ~42c a few years back; it's amazing
what you can get conditioned to. I did put electrolytes in my hydration
though..

I went back to the Norwegian summer following the summer of Black Saturday in
2009, where we got a few 46c days. That was a shocking summer even by
Australian standards. When I got to Norway it was around 35c - unusually hot
for them; my family really couldn't handle it. I just found it mild and
pleasant... they all looked at me weird.

The reverse was true when I moved to Australia many years before that.
Arriving in June, coming straight out of the Norway winter I couldn't
understand why Melburnians were complaining so much .. to me the "winter" felt
hot!

Of course I also complained that they should close the windows in the office
because of the road noise, only to discover that double glazed windows aren't
standard everywhere. They really don't know how to build houses here.

I've seen below freezing point temps riding to work now so they really ought
to introduce some proper building codes ... it's just sad how much energy is
wasted pumping heat through the metre wide gaps under the main doors. Really,
Australian builders have _NFI_ about energy.

------
DenisM
I always wear a bandana when tourusting about in hot weather. Make it wet from
a water bottle and put it on my neck for a bit of instant continuous cooling.
Put it on the head, spreading around the forehead for even more cooling. Put
it on my wrist and then occasionally wipe the forehead for occasional / no
cooling.

Another “trick” is cardiovascular health. I was miserable in heat for some
time but thing got a lot better after I picked up cycling - 32 c humid heat
produced no discomfort (apart from sweat).

------
johnwatson11218
Phoenix resident here. I find that in summer I need to limit my caffeine and
get plenty of sleep. I buy Nuun electrolyte tables for runners and drink them
all day in my water while just sitting in the office. Get your AC looked at,
make sure your duct work is not leaking any air. It is kind of expensive but I
installed a mini-split AC just for my bedroom and it is incredible. I highly
recommend a mini-split (or ductless ) AC for the room you sleep in.

------
b1daly
I’m always annoyed by the waste of cooling (or heating) a whole building when
what we really need is just our body temperature to regulated. My thoughts
drift towards clothing that has cooling built in, but become my usual muddle
of 1/1000th baked ideas.

But try putting a reusable cooling pack right on your body, it’s pretty great
when you’re overheating.

Back mounted compressor that runs cooling pipes to your underwear, that could
be amazing!

~~~
nbsd4life
look up 'cooling vest'

------
dba7dba
I grew up with no AC in a location that got very warm/humid in summer. A fan
was it.

Now I have a family member who grew up in Hawaii and consequently with AC
turned on alot.

When it gets a little warm/humid and no AC is available, it's absolutely
miserable for her. But I'm just fine. I mean it's miserable but I can pretty
much function normally. She can't.

------
crishoj
Being bare-footed (as opposed to wearing socks) also makes a huge difference.

Source: Living in South East Asia for years.

------
tiatia123
"Wear wet clothes"

Oh Man, when it is hot I love go sleep and use a wet towel as a blanket. Girls
hate it.

------
YeGoblynQueenne
And don't forget: if you have an air-conditioning unit, either close the
windows, or turn the unit off (and keep the windows open).

Unless you're trying to chill the universe, that is.

------
virmundi
I live in Florida. My AC unit in my office is out. That’s on the second floor
of my home. A beach towel sarong and no underwear. Modesty and cool.

------
projectramo
Has no one seen Scorsese's Gatsby?

You take ice, put it in front of the fan, and let the fan blow on you
combining several of these low-tech ways to keep cool.

~~~
ctrl-j
And then your freezer turns on and dumps a bunch more heat into your
environment.

Better only use store bought ice for this trick.

~~~
DoofusOfDeath
I wonder how much we'd benefit from having seasonal control over where
electrical appliances send their waste heat:

For example:

\- ovens: vent outside on hot days, inside on cold days.

\- clothes driers: vent outside on hot days, and on warm days either (a) vent
inside through a filter or (b) send the exhaust through an indoor heat-
exchanger before venting.

\- refrigerators: cooling coils cooled with indoor air on cold days, outdoor
air on hot days.

~~~
simonblack
"\- clothes driers: vent outside on hot days, and on warm days ... send the
exhaust through an indoor heat-exchanger before venting."

We live in the tropics and do not have anywhere to hang clothing to dry.

We use a heat-pump dryer which heats the air on the 'hot' side then through
the clothes and then circulates the now-moist air through the 'cold' side
which removes the excess heat and condenses the water vapour.

The same air then goes through the cycle all over again. That means no huge
amount of hot, wet air escaping into an already hot house which needs to be
either vented or cooled.

And because the energy used in heating the air is not thrown away by venting
it, but is recaptured by the 'cold' side, the dryer is cheaper to run.

------
timwaagh
number 9: eat less and dont be fat. your internal heater is your worst enemy.
if you eat little, your body starts to lower its internal temperature and this
will help you cool down. fat acts as an insulator so it is helpful to not be
fat. i've been on a diet since christmas and my only problem is staying warm
right now. i want it to be over 30 otherwise i have to layer up.

------
RcouF1uZ4gsC
_The_ solution to keeping cool indoors is air-conditioning. Given the way we
are (not) curtailing our carbon emissions, the world of the future is going to
be warmer than it is now with more frequent heat waves. Air conditioning will
literally save lives. We need to get the infrastructure and economy in large
portions of the world to the point where the vast majority of the population
will be able to afford air conditioning and the infrastructure supports air
conditioners running all the time.

~~~
djmips
So I guess animals need to develop tech to survive?

~~~
noonespecial
No they'll survive just fine without, sloshing like evolutionary sludge into
every nook and cranny that supports life as they always have.

We don't need tech to _survive_ either, so long as we don't mind living like
animals!

~~~
Jill_the_Pill
Or they won't. Sixth mass extinction.

------
hansthehorse
Fishing offshore in the summer here in Florida a wet hat is traditional, at
least in my circle.

------
malloryerik
In humid heat a simple towel to remove sweat works surprisingly well.

------
thatfrenchguy
They forgot « put your feet in ice », it works super well.

------
onychomys
That is a super cute orangutan in the article.

