Food & Water in the Cold

Cold weather is a full-body furnace: you burn thousands of extra calories just staying warm, and dehydration sneaks up on you because you don't feel thirsty.

Calorie Math

Winter travel can demand 3,000–4,500 calories a day. Fat is your best fuel: it burns slow and steady.

Weight your food toward fats: nuts, cheese, chocolate, salami, olive oil added to everything.
Eat small amounts constantly rather than two big stops — your furnace wants steady fuel.
Keep tomorrow’s snacks in a pocket so they don’t freeze solid in the pack.
Warm food matters beyond calories: a hot meal at the end of the day restores morale and core temperature.

Water: The Silent Problem

Cold air is dry air, and every breath humidifies it with your body's water. You lose fluid faster than you notice.

Drink on a schedule — roughly every 30–45 minutes — not on thirst.
Insulated bottles or water totes; keep bottles upside down so the cap doesn’t freeze shut.
Melt snow for water rather than eating it: eating snow pulls heat from your core and can chill you dangerously.
Melted snow needs purifying just like any other source; use a stove or chemical treatment, since filters freeze and crack.
A hot drink in a thermos is water, warmth, and morale in one container.

Start the day with a full bottle you can still drink — freeze-proof it the night before.

Don't

Never sleep with your water at your feet — it will freeze and steal heat.

The Thermos Strategy

A one-liter thermos is the highest-value kilogram in a winter pack.

Pre-load it at breakfast with soup, cocoa, or tea for a mid-trail warm-up.
Pre-heating the thermos with boiling water for a minute keeps drinks hot for 12+ hours.
In emergencies, hot sweet drinks are the field treatment for mild hypothermia (once the person can swallow safely).

Caffeine, alcohol, and cold

Alcohol dilates blood vessels and speeds heat loss while masking how cold you actually are. Caffeine is fine in moderation but is a mild diuretic when you're already losing water to dry air. Neither belongs in a survival situation — save the celebration for the trailhead.