As racer kids we used to duct tape the seam right above the toes. Seemed to help.

Still loving my Sidas system. Batteries always last through the day and haven't had to painfully thaw out my toes since buying them.

Not sure how they compare to Hotronics but I had a pair of Sidas boot heaters installed underneath my footbeds this season and so far I love them. I used to suffer from cold feet (froze them too many...