Taking this very very low tech... I ran a 5 day running race in 40-50C heat this summer. By grabbing ice cubes at the control points during each stage and holding them in my hands - as opposed to putting them under my cap like most runners - I was able to drop my heart rate by 3-6 beats per minute until the ice melted.
The Swedish company Craft made an "ice glove" for triathlete Torbjørn Sindballe who had trouble from the heat when running in Hawaii...
Can't edit anymore: Since finding this I've found one more study that doesn't support the CoreControl, and I've found three that do support the CoreControl, as well as 3 redditors that have said the support it.
Another thing to note is that the sample group in most of these studies is far too small (9 people, come on!)
I wonder if the use of running as a stressor effected that study? The original article caused heat in the core and upper body(squats and pullups) while short sprints is more of a leg issue.
For people not willing to buy such a contraption (like me), though the vacuum helps, try running cold water over the bottom of your wrists. It's a fantastically-effective way to cool off, and very not-messy.
A Noah Shachtman piece in Wired about tech for soldiers spends some time on this same device from Stanford and it describes how the device (in an earlier form) could also be used for warming:
Towards the end of the piece, the author describes being being in a bathtub with cold water and, after it starts to affect him, the device is used to warm him:
"But his stories get harder and harder to follow. I’ve started shivering again--all across my legs and chest, muscles pulse to a manic rhythm. And then I start having tremors. My thighs jackknife to my chest, unbidden. I moan, and darkness closes in from the edges of my vision.
Then, just like on the treadmill, Grahn takes my wrist. He slips each of my hands into a modified Glove prototype. This time, the metal hemispheres inside are hot to the touch--113 degrees. After two minutes, I can think again. The tent comes back into focus. You can stay this way indefinitely now. "You’re at a thermal equilibrium; the heat going into these two hands is equivalent to what’s going out of the rest of you," Grahn says. "Now you’re uncomfortable again -- merely uncomfortable. That’s a huge difference when you’re talking about survival." The water is still bitter, of course. But now I can take it.
> "The drugs that render patients unconscious also make them hypothermic. That’s useful because chilled patients bleed less during surgery ..."
Coagulation is an enzymatic reaction. You might not be surprised, then, to learn that low temperatures retard, not enhance, coagulation. Cold temperatures make the patient bleed more, not less. The article gets this part exactly wrong.
Is it possible that this is counterbalanced by the circulatory system's reaction to cold? For instance, perhaps surgery on the limbs is easier when the body is reducing peripheral circulation as it does in someone experiencing hypothermia.
Empirically, my understanding is that no, the harm of cold temperatures (decreased coagulation) is not counterbalanced by the gain (decreased peripheral circulation). Patients undergoing surgery are coagulopathic, moreso when they are cooled, and in fact they are often actively warmed now.
That's exactly what they're talking about. If the reason they bled less was that their blood was coagulating all over the place, they would also bleed less because they would be dead.
And yet coagulation is the relevant thing to discuss when we talk about blood loss from surgery, which is all I am trying to address because I am uncomfortable with the fact that the journalist got his facts exactly wrong. Being cold during surgery makes you bleed more. You and others have noted that cold causes constriction of blood vessels, so if that were the driving fact during surgery, cold would be beneficial. In fact, it is not. The decreased effectiveness of the clotting cascade outweighs the decrease in peripheral blood flow, leading to increased blood loss due to cold. The journalist stated something as fact, and then tried to explain why it was so. But he started from a false fact.
I think this might be bullshit. [Edit: maybe not. See thread below.] The article is from 2005, and I can't find anything that is less than 3 years old that describe the device working.
I was working as an engineer near Stanford when this cooling glove was announced, and I remember hearing about the "$400,000 version by a name-brand design firm that really never worked." It's possible that the professors just gave up or moved on to something new after discovering that productization was hard. It might also be that the rate at which you can cool a human body through the small surface area of the hands without damaging the skin is too small to be useful.
Anyone find any good evidence that this could work?
Each time I see stories about this device I end up wanting to have access to one at my local climbing gym REALLY BADLY. I hope they manage to bring the price down enough that I might actually be able to pitch it to the gym.
And if you could combine this with a machine to remove lactic acid from your forearms and make it small enough to fit into a chalkbag so that every time you dipped, you got chalked up, cooled down, and stronger. Yeah, I think that might work.
Why not? Doesn't seem to complicated - you'll just have to find the best temperature for you and a way to keep it stable - a thermostat and/or variable amount of insulation should do the trick...
They even state the temperature, between 18 C and 22 C. I'm thinking if you could find a plastic top for a gumball machine (or something like it) you would have a pretty good start. The vacuum could be done manually with a pump of some sort.
For the cooling part, you'd need to drill two large holes for a pipe to go through, which the hand would hold onto. Then maybe just have a water and ice reservoir that sits on top of the whole thing? That way, you wouldn't need any electric pumps or anything.
Then, the only thing left is sealing the wrist joint. One of those big rubber exercise bands might be enough to seal it off.
How important do you think the vacuum really is? Wouldn't it make sense for a DIY unit to just cool water to 10C and then to submerge your hands or feat in that? That would be a much more efficient method of heat transfer.
The vacuum is the key to the whole thing. The blood vessels in your extremities are very good at contracting when they get cold, to help preserve your core temperature. The vacuum draws them back to the surface, meaning you can cool much more blood more quickly.
I made a half-arsed attempt at replicating this a while back. The stuff I noted for my next attempt:
As your vacuum increases, the hand/wrist will be pulled further into the chamber. You have to have something to hold inside the chamber that is anchored to the chamber, or a container where having the fist jammed up against the back wall is reasonably comfortable. (My original attempt: using juice concentrate cans rather than flowing water through a handle. I wanted to avoid flowing water if at all possible.)
Due to the whole "arm getting pulled inside" thing, the wrist seal is more troublesome than I hoped. My next try is going to use a dry diving suit wrist-seal.
You want as small an interior volume as possible if using a manual air pump. It's much more time consuming than you'd think to hand-pump the air out and achieve the desired vacuum. I wouldn't want to risk using an automatic air pump in this case, myself, so I'm sticking with the hand pump while reducing the interior space of the container.
Let me know if you have success with this; or, heck, even if you don't, because you'll probably have some good advice as a result.
"When a hot body core issues a command to open the radiators and dump heat, the palm can override that command and order the radiators to shut down based on local conditions, i.e., if the palm touches a cold surface" - Damn, I was thinking that you could cool down by touching anything cold, apparently that won't work because the radiator shuts down if the outside conditions are too cold (so touching ice won't work)... Pretty interesting research, though - implementing something like this in some sort of "power suit" would be great.
I'm a person who almost constantly feels hot. I think unconsciously I realized that if I roll the sleeves up on my long sleeve oxfords (when I have to wear them) I feel much more comfortable, but could never figure out why it made such a difference. I suppose it just helped expose more area near my hands and cool me off.
You and I have the same problem; even in the winter, I rarely need anywhere near the amount of clothing that people around me seem to.
What's really annoying here in Tokyo is that, during the winter, the thermostat in every office, train, and department store is set to about thirty-five million degrees centigrade.
I have to strip off pretty much everything I'm wearing whenever I transition from the outside to the inside, and then put it all back on again when I do the reverse. Amazingly annoying.
What's helped me out a lot are Marmot's Gore-Tex jackets. Because they're breathable and have vents, I can just unzip a bit and cool down rapidly. Admittedly, they don't look as good with a dress shirt as a nicely-fitted suit, but it's a compromise that keeps me from bursting into flame.
No, normal BP. However, as I've gotten older it isn't as bad (and I've started to become more sensitive to cold), but I still find myself hot and sweaty when everybody around me is often fine or cold.
When I was young, it wasn't even a big deal to go out for a while in the middle of winter in a t-shirt, I didn't even own a proper winter coat until I was far into my 20s.
This is way over-engineered. Just put your hands in cold water..
Also, this fact about cooling the body for better performance is well known in professional sports. An example product that is being used there: http://www.icydip.com
The problem with that is that the blood vessels clamp down in response to cold. The vacuum prevents that, and seriously improves the efficiency of the cooling process.
I noticed the article talked about dogs cooling through their feet. I used to work in a hot office, and the best solution to cooling down was to take my shoes off and have a fan under the desk.
Luckily, I shower every day, and my feet don't generally sweat or smell too badly.
when externally applied heat shocked open the radiators in the cold palms of anesthesia patients, warmed blood was returned straight to the heart, and the body was reheated from the inside out. Applying a mild vacuum to the hand intensified this effect.
It doesn't need a vacuum, but it does help. They don't seem to mention why.
Applying a vacuum to an area causes blood to well in that area, suck on your hand and you'll see the area you suck on blush. So presumably you're making capillaries open up and increase heat transference over the skin threshold. Opening all the capillaries in an area will increase the volume of blood in that area too, so greater volume and greater heat gradient (over a small distance).
Disclaimer: Assumptions, not medically/biologically trained.
The Swedish company Craft made an "ice glove" for triathlete Torbjørn Sindballe who had trouble from the heat when running in Hawaii...