Technology
A Hotsuits Heated Kidney Belt utilises a non-toxic, food grade solution of super-cooled sodium acetate and water sealed inside an ergonomically shaped heat pack. The heat pack takes advantage of the fact that although sodium acetate 'freezes' at 54 degrees C, it is happy to remain in a liquid state at temperatures well below that. Pressing the activator button integrated into the pack triggers the process of crystallization, changing the solution from a liquid to a solid state and producing a constant heat which lasts until the solution has fully 'frozen' - this usually takes between 45 and 60 minutes.
Dimensions
The Hotsuit Heated Kidney Belt consists of a high-quality one-size-fits-all soft neoprene waist belt which weighs in at a very lightweight 130g. The actual heat pack is a svelte 260g, 23cm x 13cm x 1.2cm 'butterfly' shape.
The Hotsuits Heated Kidney Belt in Use
The heat pack is stored in liquid form in a pouch in the neoprene waist belt beneath a standard wetsuit where, due to its small form factor and low weight, it sits virtually unnoticed. When additional heat is required, the user simply pushes the easy-to-find activator through the material of their wetsuit. The process of crystallization begins immediately, which results in a pleasant warming sensation through the lower back and kidneys which gently intensifies over the first few minutes of activation. To maximize comfort and even distribution of the solution as it solidifies, it can be beneficial to massage the heat pack through the wetsuit during the first minute or so.
Recharging the Heat Pack
After use, the solid state sodium acetate in the heat pack can simply be returned to liquid form by placing the heat pack in the reactivation bag supplied, and immersing in a pan of boiling water for 10 to 15 minutes. Remove from the pan and allow the pack to cool before re-use.
Reviews:
Alex Dick-Read, The Surfers Path
While wetsuit technology at last seems to be changing after some years of neoprene stagnation, it' also good to know that a simple idea using relatively old technology can make it through the hype. Most people will have come across those sports injury heat packs containing a strange gel that solidifies and heats up when you press a small button on the pack. To recharge them again you simply put the pack into boiling water and the solid returns to gel. Aussie company Hotsuits have used this technology, shaped it appropriate to your general abdominal area, and stuck inside some neoprene. The result is a slow-warming heat-source inside your suit that lasts for an hour or so.
I tried it in midwinter Cornwall and it works though it made the most difference right at the start when the pack was hottest and the water and my muscles were coldest. And having this belt around me made no apparent difference to my ability to surf in fact I forgot I was wearing it after a while. It had an added benefit, too: these were my first few surfs since breaking some ribs, so I placed it in that general area. The extra warmth had a soothing, loosening effect which I think will be welcome by any cold-water surfer suffering from lower back, kidney or any other abdominal pain or stiffness. So it's thermal and therapeutic and could really help get you out there on those freezing days when the waves are good but the body's trying to chicken out.
Bill Woods, Diver (Alaska)
Up here we dive drysuits all year round. I have a dodgy back and I thought I would give the Hotsuits Heated Kidney Belt a go. I was pleasantly surprised that I could still activate it through my tri-laminate drysuit even wearing a 5mm glove.
Max Larsson, Surfer (Sweden)
Last week it was -10c air temp, snow on the ground and about 2c in the water. Normally I only last about 30 mins wearing a 6/5/4 with hood, gloves and booties. Since I have purchased a heated kidney belt I have more than doubled the time in the water.
