How do I prevent cold feet in Nordic boots?

Cold feet are a common Nordic issue due to lower heat generation than alpine skiing. Strategies include: (1) Ensure boots fit properly—too tight restricts circulation, (2) Use quality merino wool Nordic socks, not cotton or thick alpine socks, (3) Add aftermarket insulated insoles, (4) Choose boots with built-in insulation or reflective heat liners for cold conditions, (5) Keep your core warm—cold extremities often start with inadequate core insulation, (6) Do up your laces snugly but not overtight, (7) Stay active and maintain pace to generate body heat, (8) Use chemical toe warmers on very cold days.