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Seirus Heatwave Sock

photo: Seirus Heatwave Sock snowsport sock

This is a very thin oversock with a Thermodynamic inner surface. To be worn over any type of sock for additional warmth.


  • Adds extra warmth through radiation
  • Very thin for easy fit
  • Stretchy so it doesn't bunch up


  • Only good for 10-15 degrees of warmth

The Seirus Heatwave sock uses Thermodynamic principles to radiate your foots heat back into your under sock for extra warmth. This is a simple super thin sock with a coating on the inside that in worn over any type of sock. A size medium worked well for my size 9 feet and they slipped over my ski socks easily. The stretchy fabric allowed them to hug my feet without adding any bulk and my feet slid into my ski boots as always.

I tested the Heatwave Sock for a week on a Canadian ski trip where temperatures ranged from 5 to 20 degrees Fahrenheit. I thought on the 5-degree day worn over medium thick wool ski sock that they worked rather well to keep my feet warm for about 2 hours. My feet felt much warmer early in that period, but the warmth fell off as my ski boots got colder and colder on the outside. They worked for about an hour after a lunch break allowed my feet to warm up again.

As the days got progressively warmer the heating radiating properties of the socks increased until when the temperature reached 20 degrees the warmth was lasting all day. I am sure part of the reason for this is that while skiing your feet don't really move all that much, and on chairlifts they don't move at all. Since you are not producing a lot of heat there isn't much to radiate back to the feet.

While I haven't had a chance to prove it, my impression is during a more active sport like snowshoeing or hiking the benefits would increase. They could also be worn for any type of winter outdoor work environment where the wearer was moving around consistently.


While the Heatwave socks aren't inexpensive, rated for cost next to chemical foot warmers they would be cheaper over the long run. On the days with temperatures between 10 and 20 degrees, I felt the socks matched the performance of chemical foot warmers.

Product information:

  • Size: small-XLarge
  • Color: Black
  • Price: $34.99


Source: tested or reviewed it for the manufacturer (I kept the product after testing.)

Disclosure: The author of this review received a sample of the product from the brand or its representative in exchange for a review.

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Price MSRP: $34.99
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