Hotronics FootWarmer S4 Custom insole kit

Given the frostbite damage I suffered on Manaslu I decided to limit the possible future occurrence for my feet.  I purchased a set of Hotronic FootWarmer S4 Insoles.  There is a video on YouTube by "Peter Glenn Ski & Sports" for the installation.

I decided to install this myself -scary when you are cutting into an expensive La Sportiva Olympus Mons inner boot.

The Hotronic works pretty well in that it can generate good heat at a high setting.  At the lowest setting it is just 'feelable'.  It is a matter of finding the best setting for the temperatures that one experiences.  It is important not to overheat the toes/foot as it will cause sweating and 'wet-out' your socks...making them unable to trap air for warming.

These insoles look well constructed and I will have the ability to test in anger when I go to Broad Peak in June 2016.

Installation approach below:
Step 1) Make sure that the insoles work before installation.  This is so that you do not waste time installing a permanent setup if there is a fault.

Then follow Peter Glenn's instructions.

Attached are the pics of my installation.  The heated insoles work well (tested in my house as I am not on an expedition at the moment).

Made a slit in the insole and put the cable through.  Then secure the green and bottom sticky backing to fix the heating element and cable in place.

Now stick the top cambrelle lining by centering and then work backwards towards the heel by peeling back the white backing.  Cut slits to help the folding over of curved edges.

Now measure the inner boot "T-shape" slit.  Avoid compromising the spine stitching.

Secure the cable.  Now you are done.  Put the inner boot back in and test.  How you choose to deal with excess cable is a personal choice.  I prefer not to fold and bend the cables.  A little bit of excess cable in not an issue as it makes handling when connecting the battery much easier.