Alpinestars Cooling Vest in grey

Now the Alpinestars cooling vest is a very specialist, and a very special, bit of kit. We used to do a very similar vest from Macna, but that now seems to have been withdrawn from the market.

 

The vest utilises what is known as 'evaporative cooling' to reduce the body's temperature. There's nothing new in the technology. Indeed, evaporative cooling is basically how sweating works. The military has used the same idea for many years. It's how soldiers fighting the Afrika Corps in the deserts of North Africa would have tried to stay cool. It's the same principles that people like the Marines would employ even today.

 

But first let's talk about the principles. What evaporative cooling is. How it works. And how it serves to lower your temperature. The most apposite explanation of evaporative cooling is to talk about it in the context of sweating.

 

When we get hot, our sweat glands secrete a solution to the surface of the skin. The process of that liquid sweat turning into a vapour in order to escape from the body requires energy. That energy is drawn from the body as heat, and this cools us down. 

 

Sweating is the body's in-built mechanism for cooling itself down. But there are times when it is so hot that sweating alone will not be able to sufficiently cool the body down. In such circumstances a little extra help is required. A cooling vest can provide that bit of extra help. The principle is the same, but with a vest there is more liquid being turned into a gaseous state. Because of this more heat is generated, and so more heat is absorbed from the body, thus increasing the degree of cooling.

 

When the water in the vest reaches the appropriate temperature it will start to evaporate through the vest's external, breathable surface. And when this happens you will start to enjoy the benefits of evaporative cooling, but on a scale that could never be replicated by the body alone. And so if you are riding somewhere really, really hot a cooling vest is a very effective way of staying cool.

 

But there is one thing. You need to be wearing an outer jacket that is very breathable. Something like a Marrakesh, an Induction, a Baja S4 or a Vihti. The more breathable the better. A traditional mesh jacket will work, although not as well as a jacket that breathes through every panel. A cooling vest won't work beneath a waterproof jacket, and that's because for any kind of evaporative cooling to work - and that includes sweating - the liquid has to be able to evaporate. And if you're wearing a waterproof jacket the water won't evaporate. It will remain in its liquid form.

 

There's one other thing you need to be aware of. The cooling vest will be extracting liquid from the body. And when it does you need to be drinking water to replace it. A cooling vest will cool you down, but if you're not drinking sufficiently, dehydration and heat exhaustion remain an ever-present possibility.

 

We spoke earlier about how soldiers used evaporative cooling to reduce their temperature. But back in Tobrul Monty did not have access to cooling vests, and so soldiers would simply soak their shirts in water, wearing them perhaps over a wet towel. It was less sophisticated, perhaps, but the end result was the same. Water evaporating. Heat being used as the energy to make that happen. This heat being extracted from the body. A cooling effect on the skin.

 

The Alpinestars vest operates in exactly the same way as the old Macna one. You put half a litre of water into it. You then massage this to spread it evenly around the vest, as you want the maximum contact you can get with the body. As the body heats up, the temperature of the water will rise to a level where it will start to evaporate. You will start to cool down. Put too much water into the vest and it won't heat up as effectively, thus reducing the cooling effect. A half a litre in the vest should last for two to three days in hot conditions.

 

You will see that the vest is covered with small holes. And these are important as they will allow the oncoming air to cool your skin. These will also help the sweat generated by the body on the inner side of the vest to evaporate. 

 

There are some comments online about the sizing of these vests, and how they are only applicable to tiny, little people, but that is unfair, and not the case. The largest size goes up to a 48" chest, which is not Lilliputian. But whilst the vests have stretch built into the sides for a more comfortable fit, it is probably true that these vests do not work so well with large tummies. Large chests are fine; large tummies not so much.

 

In really, really hot conditions there's no better way of trying to keep a lid on your body temperature than a cooling vest.  Macna used to claim that their cooling vest could reduce your skin's surface temperature by as much as 15 degrees. And if that is true it's going to be no different with the Alpinestars one. Finally, do not underestimate the potentially dangerous effects of heat exhaustion. It creeps up on you. On minute you're feeling fine, and riding well. The next, you're keeping a lookout for cactus trees, before turning off the track and riding straight towards them! As we said, it's dangerous. And so if you're headed anywhere really hot this summer, this might be the answer.