Dealing with the Heat

A while back, I wrote a post about overheating in the iPad – how too much heat renders the iPad useless because it just shuts down. When that happens, you could either remove the iPad from an external heat source (e.g. direct sunlight), allowing it to cool passively; or apply some form of active cooling to it (chemically, mechanically, or electronically). Then once the internal temperature has dropped below the “shut-down threshold”, the iPad usually performs normally again.

Athletes can also suffer from an ‘overheating’ type of situation and in some cases can lead to hyperthermia. Due to an extended period of high intensity physical exertion, and/or being in hot and humid conditions, an athlete’s core body temperature could go up to say 40 degrees C. Lots of studies have shown that this (excessive heat) can have a negative impact on the athletes’ exercise performance (or muscular endurance) and possibly some adverse effects on certain cognitive abilities.

So how do we deal with this heating issue that affects athletic performance? On top of ensuring proper hydration and sticking to safety guidelines (mostly common sense), there are a number of cooling strategies and technologies that could keep athletes cool, which then prevents heat illnesses, and ultimately helps maintain performance.

Heat Acclimatisation

Although not exactly a cooling strategy, heat acclimatisation is a common practice for athletes living in cooler climates and preparing to compete in warmer and humid climates. The acclimatisation process might involve moving to another location with similar weather to live and train, or it could be training in an indoor controlled environment where heating and humidifiers are applied. Basically, the aim is to get the athletes accustomed to the higher air temperatures and so reduce the impact of heat on their performance. In some cases, heat chambers are also designed to be hypoxic chambers so athletes can also be conditioned for high altitudes (which would be handy for events like the 2010 football World Cup).

An example of PAFC players training in a heat chamber in UniSA (source:

Cooling Strategies 

Pre-cooling is the process of cooling athletes before performing any exercise. There is evidence to show that pre-cooling procedures benefits athletes in endurance sports, and to some extent athletes in team-sports that require high-intensity repeated sprints (study link). It was gathered from this article that whole body pre-cooling is the more effective cooling procedure compared to only upper body cooling using cooling vests such as the adidas adipower or game ready vests. Although logistically, preparing the equipment for whole body cooling may take a bit more effort, compared to just distributing a bunch of cooling vests to the athletes.

An Example of a Portable Ice Bath from icoolsport

This article looked at a half-time cooling strategy that involves getting the soccer players to immerse their forearms and hands in 12 degrees water and putting a cold wet towel (that was previously soaked in 5 degrees water) around their neck. Their results showed that this primitive active cooling method significantly reduced the athletes’ body core temperature in 15 minutes.

A Novel Cooling Tech

A company called Avacore Technologies developed a novel technology that allows an athlete to cool down by simply wearing a specialised glove. How it works relies on the fact that the palm of our hands are radiator surfaces; which means when our body temperature goes up, blood flow naturally increases through those (radiator) skin regions to dissipate heat. This is achieved through special blood vessels called arteriovenous anastomoses or AVAs.


Retia Venosa

The glove system known as Rapid Thermal Exchange (RTX)  was invented by two Stanford biologists who were doing research on thermal-regulation. The system not only regulates a continuous flow of cool water through a pad (or grip/cone) which the user’s palm maintains contact with, it also creates a slight vacuum within the glove and that limits the blood vessels from constricting, which allows better blood flow and ultimately better cooling. There is a lot more explanation on their FAQ page, and links to scientific studies/evidence at the bottom of the page here. Or if you prefer to watch a video, check out this one from CNET where the presenter actually did a test herself and showed that it actually works – cooling her significantly and improving her endurance.

[A side note on the video: using an ingestible temperature sensor would have saved the presenter from that gagging experience (around 1:40 of the video)]

So not only is this glove technology keeping athletes cool and preventing diminished performance, coaches are seeing their athletes push harder and longer when the RTX is used in between training sets. The rates in gain is so dramatic that the gloves have been labelled as more effective than steroids. But even with such good reports, not everyone is rushing to purchase these gloves yet. As mentioned in their paper, the inventors recognised that there are a few barriers and one of it is people’s resistance to new views. Another challenge is to develop something more compact or even wearable, so that it increases the potential of effective application in other areas such as mining, firefighting, or emergency services.

Recently, Avacore launched an Indiegogo campaign to crowdfund their new consumer version which is just one standalone portable device instead of a few components. Looking at the number of backers, I would say it was very well received.


Different versions of the Avacore Cooling “Glove” (

Something for the makers and tinkers

Interestingly, someone who really liked the product but thought that the CoreControl Pro version was too expensive, decided to make a DIY version for a fraction of the price. He even made a CoreControl DIY Instructable. Based on the comments, there’s at least 2 other people who followed the instructions and built one for themselves. One other guy even made some improvements and published his own guide on how to build it.

Closer to home, a mate of mine also attempted to develop a product similar to Avacore’s hand cooling concept. One main difference is that his design does not require the use of ice and water, something that most of the methods mentioned earlier use. Instead, his entire system is electromechanical, very portable and can be easily switched between cooling or heating. If anyone in Melbourne would like to be one of the first few to trial his prototype, drop me a message/comment and I could help organise something.

Finally, with all the cooling technologies and methods out there for athletes, I think something that will really complement them, is a wearable temperature sensor (such as the cosinuss) that can constantly monitor body core temperature. That way, coaches can know exactly when to stop the athletes from their activity and stick their hand into a body cooling glove.




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