As you can see, it is a very warm sock. With 100% synthetic construction, the FLAMES is a midweight sock for those that understand that--when it comes to foot comfort--circulation is more important than insulation. If you have a slightly wide foot, shaving a few mm of waist width on the sock will improve the speed and accuracy of your comfort. Also, just to counteract the heat of the flames, it had to be midweight. So it wasn't too hot. Still so hot tho.