I live out in Dallas, TX and we hit the 100 F before the official end of Spring. At the my last race, a week ago Saturday, the heat index was 113 F by 3:30 in the afternoon. I think the official high was 101*F, but the humidity made it miserable.
Back up a few weeks and I was passing a guy in the hall at work. He is a porter for our new car department at the Dealership I work at. He was wearing a vest of some kind. Jokingly I ask if wasn’t going to be hot wearing that around outside. He spends much of his time walking the car lot and moving cars around. He chuckled a little and said, “No! It’s a Cool Shirt!”. “How does that work?” I replied. He explained that the inside of the vest was lined with pockets front and back that you inserted little frozen pouches into. It also had a liner to buffer the cold from direct contact with the skin. It was supposed to last for a couple of hours. I immediately thought of Max Verstappen during the grid walk interviews wearing vest that had little ice packet on it.
This got me thinking over the next few days. I wonder how well that would work under my kart suit. I did a little research and found a lightweight vest (under 5 lbs) with interchangeable phase change liquid packs. The manufacturer claimed the packs would maintain 59F for up to 2.5 hours in 100F and could easily be reactivated in 30 minutes in ice water. That sounded perfect for the track. I ordered it and spare set of cooling packs to swap out throughout the day.
When they arrived I tossed the cooling packs into the freezer. A couple of days later when it came time to racing, I pulled my Mini-Cube Coleman cooler to store the packs leaving my Coleman Cube for plenty of water, ice and a few sugar free sports drinks. In addition to following my normal hydration routine of alternating a couple bottles of water with 16 oz of sport drink (or mixing up some Skratch Powdered Drink Mix) throughout the day, I wore the cooling vest during the sessions. I wasn’t sure at first how cold it was going to be so close to the skin, so in addition the UnderArmor shirts I usually wear I brought a cotton T along just in case. Amazingly the athletic shirt was more that enough. It wasn’t freezing my skin, but definitely had a cool sensation. Normally as the day progresses, the heat starts taking its toll on me. Especially by the end of the long Main. That day it wasn’t bothering me in the least. Even at the end of the Main, I was as cool as a cucumber. Sure, it was still hot out, but I wasn’t feeling it like I normally would. Meaning to say there were a few times last summer I thought I was about to have a heat stroke in the scale line. Not this time.
That day I was telling everyone that would listen about the cooling vest. I even suggested to the track staff they they should get some for the corner workers to wear. Those folks get the brunt of the heat exposure! The vests come in different colors and even have reflective neon like for road work crews. They would be perfect.
I discovered another benefit over the next two days. To back up a little, I take my Yeti-like cup to work with me everyday and typically refill it several times throughout the day with water. Starting a day or two before a race, I will mix in a sport drink or two. I pretty pound fluids all through the day on race day and continue through the evening and following day. Despite all of that, I was waking up a few time in the middle of the night with severe leg and hand cramps. Often my hands would start cramping before the last race. Changing nothing else and despite it being the highest heat index I have ever raced in, I did not get a single cramp! I call that a major win!!
Here is a link to the one I bought.
I ordered them through Amazon and paid $199 for the vest that came with 8 cooling packs and an extra 8 packs for $139 to swap out with throughout the day. The vest holds two smaller 3 cell packs in the front and two longer 4 cell packs in the back. I was a little worried how comfortable I would be with the frozen packs between my back and the rib vest and the seat, but I could barely tell they were there other that that cooling sensation. I will say, they did not last more than an hour before they were almost completely melted. Its possible that with 2 pack per pocket they would last significantly longer, but would be much bulkier too. I was able to run a Quali, a Heat and a Main and still have one set of packs left in reserve. I did not have a chance to test the recharge in ice-water in 20 minutes feature. I think their claim to that time table is based whoever is wearing it not doing strenuous activities either.
I am not endorsing this brand over any other, but just wanted to share my experience with a product like this. I think it is a definite add to the racing gear for any driver that has to deal with racing in excessive heat. They are also available in children’s sizes for the little ones to keep their cool.