Water, Food, and Hygiene in Winter

Lesson Overview

Three of the plainest defences against the cold are the ones most easily neglected on a busy task: drinking enough, eating enough, and keeping clean and dry. Each is harder in winter than in summer, and each matters more, because the cold punishes neglect that warmer weather would forgive. A flask freezes; a meal goes cold before it is eaten; washing the feet in a freezing wind is the last thing a tired member wants. So the easy thing is to skip all three, and the member who skips them slides, without noticing, into the state the cold is waiting to exploit: short of water, short of fuel, and harbouring the wet, dirty feet that the cold can cripple. This lesson explains why the body quietly loses water in the cold without ever feeling thirsty, how to obtain and treat water when everything is frozen, why a member must eat more and take regular hot food and warm drinks, and how to keep up the hygiene, above all the care of the feet, that keeps a member healthy and in the fight.

This serves both reasons the course turns on. It keeps you effective, because a member who is dehydrated, underfed, or footsore tires fast, thinks slowly, and chills quickly, which is the beginning of becoming a second casualty rather than a help. And it keeps others alive, because the warm sweet drink, the hot meal, and the dry pair of socks are among the simplest and most valuable things the Army carries to a cold-stricken person on the winter operation. None of what follows is comfort for its own sake; it is method, and the method is a defence against the cold.

By the end you will be able to explain why dehydration is a hidden danger in the cold and how to prevent it, describe how to obtain and treat water in winter and keep it from freezing, explain why the body needs more food and hot meals in the cold, and describe the winter hygiene that prevents illness and cold injury, above all the care of the feet.

This is the knowledge layer. The recognition and treatment of dehydration and cold injury are taught and certified in person in the Combat First Aid course; this lesson teaches the prevention on which that work rests. Where it names a sign for you to watch for, it does so for recognition and to tell you when to act or call for help, never so that you treat the sick or the chilled yourself.

Key Terms

• Dehydration: the state of the body having lost more water than it has taken in, which saps strength and judgement and worsens cold injury.
• Cold diuresis: the body's tendency in the cold to shed water as urine when blood is drawn in from the skin, one of the quiet ways a member loses fluid without noticing.
• Insensible loss: the water the body loses without feeling it, chiefly in the breath and in sweat that the dry cold air carries off before it is seen; the largest part of the winter water loss.
• Potable water: water that is safe to drink, either from a clean source or made safe by treatment.
• Field hygiene: the discipline of keeping the body, clothing, and surroundings clean enough to prevent illness in the field.
• Foot discipline: the routine of keeping the feet clean and dry and changing wet socks at every chance, to prevent non-freezing cold injury.
• Ration discipline: the planning and sparing of fuel and food so that there is enough to melt water, cook, and eat hot for the whole length of the task, not just the first day of it.

The hidden danger of dehydration

Dehydration is among the cold's most dangerous tricks, because it does its damage before a member feels anything is wrong. The body still loses water steadily in the cold, and by more routes than most people expect. It loses water in the breath, because the dry winter air must be warmed and moistened by the body before it reaches the lungs and is then breathed back out carrying that moisture away; this loss is large in hard cold air and climbs the harder a member breathes, so a snow slope drives water out of the lungs as surely as out of the skin. It loses water in unfelt sweat, because hard work in heavy clothing makes a member perspire even in the cold, and the perspiration is soaked up by the clothing or carried off by the dry air before it is seen. And it loses water as urine, because the cold draws blood in from the skin to protect the core; the body then has more fluid than its shrunken circulation needs, and sheds the surplus. This is cold diuresis, and it is why a member passing water often on a cold day never connects it with the thirst they do not feel.

The trap is that none of this triggers thirst. In hot weather a person feels the water running off them and drinks to replace it; in the cold the loss is invisible and the thirst is dulled, so a member drinks far less than they need and slides into dehydration without knowing it. A second trap is layered on the first: water is troublesome in winter, the bottle half frozen, drinking meaning a bared hand and a broken routine. So the cold removes the warning and raises the cost of heeding it, and members in winter are very commonly short of water without knowing it.

A dehydrated member tires quickly, thinks less clearly, and, worst of all in winter, is more vulnerable to cold injury, because a body short of fluid has thicker, slower blood and cannot move warm blood out to the hands, feet, and face as it should. The fingers and toes that depend on that warm flow are the first to suffer, so dehydration and frostbite are partners, not separate dangers. Dehydration also makes a person feel cold and listless and saps the will, which is itself a danger, because the cold is beaten by the will to keep the routine and a member who has dried out has less of that will left.

The defence is simple and must become a habit: drink regularly, whether or not you feel thirsty. Because thirst cannot be trusted in the cold, the drinking goes on a plan: a deliberate drink at every halt and with every meal, a sip from a warm flask on the move where the task allows, and a good drink before sleep and another on waking. A leader makes a point of it, calling the drink at halts as part of the routine, because a section that drinks together drinks enough and a member left to their own thirst does not. The aim through a working day is a steady intake spread across it, not a single flask drained in the morning and nothing after, because the body cannot store a morning's water against an afternoon's loss.

The readiest check a member carries is the colour of the urine, and it is worth using deliberately.

   THE URINE CHECK  (the readiest guide you carry)

   plentiful and pale (pale straw)    you are drinking enough; carry on
   getting darker, less of it         a warning; drink more, now
   scant and dark (deep yellow)       you are already dehydrated; drink
                                      steadily until it pales again
   (first water of the day runs a little darker; judge by the rest)

Warm drinks are better than cold in winter, because they replace water and add a little heat at once, and a hot drink at a cold halt does real work and lifts the spirits. Drink against the cold should never mean alcohol, which dulls judgement, suppresses the shivering the body needs, opens the skin's blood vessels and speeds heat loss, and increases the flow of urine and so the loss of water, all while leaving a person feeling deceptively warm, as Lesson 01 set out. On the winter operation a member offered a drink to "warm up" declines it for exactly these reasons, and understands why a cold-stricken person must never be given it.

Obtaining and treating water in winter

Water is rarely far away in the Kaharagian winter, but it is often locked up as snow or ice, and getting it back into a drinkable form costs time and fuel that a member must plan for. Wherever running water can be reached safely, from a stream or a tap, it is the first choice, because melting snow or ice is slow work and burns a great deal of fuel for a small return. Where snow must be used, the return is poorer than most expect: light, new-fallen snow is mostly air, and a full pot yields only a little water. So prefer ice to snow and dense old packed snow to light fresh snow, because both hold more water for the heat spent and burn less fuel for it. Gather from a clean, undisturbed surface away from any track, camp, or fouling, scraping off the loose top and taking the cleaner snow or ice beneath, and keep the gathering vessel clean, because melt-water carries down whatever the snow held.

Snow and ice must be melted and warmed before drinking, never eaten. Eating snow to quench thirst is a costly mistake, and it is worth being exact about why. Melting ice to water and then warming that icy water to body heat both draw heat out of a member who can least afford to lose it, so a member who eats snow chills the core, drives down the very temperature the whole course is about defending, and gets only a mouthful of water for it. Worse, packed snow or ice pressed against the lips and tongue can freeze and injure the mouth. The thirst is not eased and the member is colder than before. So snow and ice are melted in a vessel, never taken into the mouth, however dry the throat.

The sound method of melting is plain, and the order matters:

   MELT AND TREAT SNOW  (the sequence, in order)

   1. GATHER  clean, dense snow or ice from undisturbed ground;
              prefer ice, then packed snow, to light fresh snow
   2. PRIME   put a LITTLE water in the bottom of the pot first,
              so the snow has water to melt into and does not scorch
   3. MELT    add snow a little at a time over gentle heat;
              stir, and keep topping up as it shrinks down
   4. WARM    bring the melt up to a good warmth (and to the boil
              if you are treating it by boiling)
   5. TREAT   treat the melt as DOUBTFUL WATER by the methods of the
              Field Health course: boil, OR purification tablets,
              OR a proper filter; clear is not clean
   6. STORE / CARRY  keep it warm, close to the body, off the ground;
              melt extra at night, ready for the morning

The priming step is the one most often skipped, and it matters: dry snow against hot metal scorches, taints the water, and can burn the pot dry, while a little water in the bottom gives the snow something to melt into and protects the vessel. Because melting is slow, a member keeps warm water on hand whenever they can and, above all, melts water in the evening ready for the morning, so the day does not begin with a cold, slow chore at the hour the body is least willing to do it; a flask of hot melt filled before sleep gives a warm drink in the night and a head start on the day.

Melting snow makes water; it does not make it safe. Treat the melt as doubtful water by the methods of the Field Health, Hygiene, and Sanitation course. Snow and ice from clean, undisturbed ground are usually low in risk once melted, but melt-water still carries down whatever the snow held, which a member cannot see, and surface water drawn from a pond, a lake, or a stream cannot be trusted by its look at all. So the rule of that course governs here: clear water is not clean water, and doubtful water is treated before it is drunk. The same three methods apply, with a winter twist to each. Boiling is the surest and needs no measuring, and is convenient in winter because the melt is over the stove already, so a true rolling boil costs only a little more fuel and makes it safe. Purification tablets work, but the cold slows the chemical, so for cold water the dose is increased and the contact time lengthened exactly as that course teaches; a tablet dropped into near-freezing melt and drunk straight off has not done its work. A proper filter rated to remove the disease-causing organisms can be used, but must be guarded from freezing, because an element that has frozen once may be cracked inside and no longer safe, and will not pass water at all. Whichever method is used, the discipline carries over whole from the Field Health course: choose the cleanest source, clear it, make it safe, store it covered and clean, and keep the clean strictly apart from the dirty.

Water must also be kept from freezing once it is carried, because a bottle turned to a block of ice is useless at the moment it is most wanted. Fill it warm rather than cold, since warm water carried close to the body stays liquid far longer; carry it inside the clothing against the body, not in an outside pouch where it freezes first; and at a halt keep it insulated and off the cold ground rather than standing it on snow or stone that draws the heat straight out of it. Two old tricks help: water freezes from the top down, so a bottle carried mouth-down (where it will not spill) keeps its cap and opening clear of ice rather than sealed shut by a frozen plug, and a bottle filled only part full has room to be shaken, which slows freezing.

Eating more, and eating hot

The body makes its heat by burning fuel, and in the cold it burns a great deal of it: warming every breath of cold dry air, replacing the heat the cold air and ground draw out of it without cease, shivering, which is the body burning energy on purpose to make heat, and driving a member through snow over rough ground under heavy clothing and a loaded pack, all far harder work than the same distance in summer. Add these together and a member at work in the cold burns markedly more energy than in the warmth, often a great deal more, and that energy has to come from food. A member therefore needs to eat more in the cold than in the warmth, and to keep eating even when appetite is low, because food is the fuel the furnace burns to keep the body warm. A member who eats too little feels it within a day or two as fatigue, listlessness, feeling cold all the time, and a flagging of will, and a hungry member chills faster than a fed one because there is less fuel for the fire.

What the body burns matters as much as that it is fed. The winter diet leans on fats and carbohydrates, which between them give the slow, steady and the quick heat the cold demands. Fats are the dense, long-burning fuel, the most energy for the least weight carried and a heat that lasts; carbohydrates are the readier fuel the body turns to warmth quickly, which is what a chilled member needs at once. A practical winter meal carries plenty of both: a hot main meal built around fats and starches, and ready carbohydrate snacks, chocolate, biscuits, dried fruit, kept in a pocket to eat on the move. The exact ration is set elsewhere; the principle is that winter eating is more food, eaten more often, rich in fats and carbohydrates, and not allowed to lapse because the cold has dulled the appetite.

Regular hot food and warm drinks are worth far more than their calories alone, and the warming they do is real. A hot meal puts warmth into the body directly and gives the chilled core something to work with, and eating turns the body's own furnace up, because the work of digesting makes heat, so a member is warmed twice over. A hot meal also lifts morale as little else does on a bleak task, and morale is not a soft thing in the cold: the will to keep the routine, to drink, to change the socks, to keep moving, is what beats the cold, and a hot meal restores it. So the discipline is to eat hot and to eat often. Frequent small intakes serve a member better than one large meal and a long fast, because the body fed little and often keeps a steady fire, while the body left long and hungry lets the fire sink and the member chill in the gap. A good meal before sleep, in particular, helps a member stay warm through the night, because the body makes extra heat as it digests through the first hours of sleep, which is exactly when a member lies still and cools.

A member can hold the day's drinking and eating together as one short check, run at every halt:

   WINTER HYDRATION AND ENERGY CHECK  (at every halt)

   DRINK    a deliberate drink now, warm if you have it;
            judge by urine, pale and plentiful is the target
   EAT      something now, even a snack; fats and carbohydrates
   HOT      a hot meal and hot drinks where the task allows;
            a meal before sleep to stay warm through the night
   OFTEN    little and often beats one big meal and a long fast
   (do not wait to feel thirsty or hungry; the cold dulls both)

Cooking and the rationing of fuel

Everything in this lesson that needs heat, the melting of snow, the warming of water, the cooking of a hot meal and the brewing of a hot drink, draws on the same scarce thing: fuel. In winter, where snow must be melted before there is any water at all, fuel is spent fast and runs out faster than the unprepared expect, and a member who burns through it carelessly in the first day may face the rest of the task with no way to melt water or cook hot. So fuel in winter is rationed and managed with the same discipline as water and food, and this ration discipline is itself a defence against the cold, because the member who runs out of fuel runs out of water and hot food together.

The management is practical. Plan the fuel for the whole length of the task, not just the first meal, and reckon honestly how much of it the melting of snow will eat, because melting is the heavy cost and is easily forgotten when the snow is all around and looks free. Cook and melt efficiently: keep a lid on, which holds the heat in and cuts the fuel and time to melt or boil by a large fraction; shelter the stove from the wind, which otherwise steals the heat off the pot; and start with dense snow or ice rather than light snow, so each unit of fuel returns more water. Heat in batches rather than firing the stove up again and again, melting and boiling a good quantity at once for drinking, cooking, and the flasks. Where a fire is the source of heat, melt and cook on it while it burns rather than waste the heat. Remember the fire and stove safety taught in Lesson 04, which the close, sheltered conditions of winter make more important, not less: a stove run inside a shelter needs ventilation against the silent danger of its fumes, and nothing is dried so close to a flame that it scorches or catches. The aim is plain: make the fuel last the task, so there is always the means to melt water and put a hot meal and a hot drink into the team, from the first day to the last.

Hygiene in winter, and the care of the feet

Keeping clean is harder in the cold and sorely tempting to let slide. Water is frozen or scarce, baring the skin to a freezing wind is the last thing a tired member wants, and it feels, on a bitter night, like a luxury that can wait. It cannot. Hygiene remains a real defence against illness, and a member who falls sick in winter becomes a casualty rather than a help, at the very time and in the very cold where a casualty is hardest to look after and slowest to recover. The basic field hygiene already taught in the Field Health, Hygiene, and Sanitation course still applies, adjusted sensibly to the cold rather than abandoned to it.

Hand-washing keeps its first place even in winter, because it is the habit that prevents disease rather than merely discomfort, and a stomach illness on a cold task is a serious matter: vomiting and diarrhoea strip water and salts from a body already fighting to stay warm and watered, and turn a working member into a stretcher case fast. So a member washes the hands before eating and after using the latrine without fail, and where freezing water forbids a full wash, a hand-cleaning gel or a clean wipe keeps the habit alive. For the body, the strip wash of the Field Health course is the winter answer: a little warmed water and a wetted cloth, used quickly in what shelter and warmth there is to wash in order the face, armpits, groin, and feet, working clean to dirty, then drying at once and dressing before the chill takes hold. A member stays serviceable on very little water this way; where even that cannot be had, a wipe-down and a change of the layer next to the skin does much. Underclothing and socks, which soil fastest and whose dirt mats the fibres and crushes out the warm air as Lesson 02 set out, are changed when they can be and aired and turned when they cannot. The teeth are cleaned night and morning as in any field routine, with warmed water so cold water is not held against chilled gums. None of this is comfort for its own sake; it is the means by which a member stays well enough to do the work, done quickly and in shelter so the cure of dirt does not become the new danger of cold.

Above all of it stands the care of the feet, the single most important piece of hygiene in this lesson and, in the wet Kaharagian winter, a daily duty and not a nicety. Non-freezing cold injury, the trench foot of Lesson 01, comes from feet that are cold and wet for hours on end, and it can cripple a member without a single degree of frost, the sodden skin breaking down, whitening, and turning raw and useless. The feet are at the greatest risk because they get wet most easily, from outside and from their own heavy sweating inside the boot, and because they bear the body's weight on the cold ground all day; the member who lets them go can be put out of the task by their own feet alone. The discipline that prevents it is the foot drill carried over from Lesson 02 of this course and from the Field Health, Hygiene, and Sanitation course, and it is plain and unrelenting.

   THE WINTER FOOT DRILL  (kept up daily, and at every good halt)

   - boots loose, never tight: tight boots squeeze out the warm air
     and choke the blood, which invites cold injury
   - INSPECT the feet at least once a day; look for soft, white,
     wrinkled skin, the warning of trouble coming
   - at the halt and before sleep: boots OFF, feet dried and rubbed
     to bring the blood back, a DRY pair of socks on
   - the wet socks go to dry against the body or by the stove,
     so a dry pair is always coming back into the cycle
   - never sleep in wet socks; sleep dry-footed
   - a little foot powder on clean, dry feet helps keep them dry
   - deal with any hot spot the MOMENT it is felt, before it blisters

The drill runs on a simple rotation of socks: carry several pairs kept dry in a waterproof bag, treat a wet sock as a thing to be got off the foot rather than endured, and dry each worn pair against the body or by the stove so a dry pair is always coming back round. The daily inspection is the same fixed check the Field Health course teaches: look for the soft, white, wrinkled skin that warns of cold injury coming, and deal with any hot spot the moment it is felt, before it blisters. The hands deserve the same watchfulness, kept covered, dry, and warm and worked from time to time to keep the blood flowing into the fingers, because chilled hands grow clumsy and slow at every task the cold makes urgent, including the very task of looking after the feet. A member who looks after their feet and hands stays effective; one who neglects them can be put out of action by the cold alone, and on the winter operation this same knowledge tells a member that a rough-sleeper's soaked, freezing feet are not a small discomfort but the start of a real injury.

Waste and sanitation in winter

The disposal of human waste and refuse does not stop being a duty because the ground is frozen, and the rules of the Field Health, Hygiene, and Sanitation course hold in winter exactly as in summer: waste is disposed of properly and kept well away from and downhill of any water source and any place where water is drawn or snow is gathered for melting, so nothing fouls the supply. Winter makes this harder and tempts the careless to cut corners, and the corners must not be cut. Frozen ground resists digging, so a member may be tempted to foul the snow nearby rather than make a proper job of it; but waste left on or in the snow does not break down in the cold, it freezes and waits, and when the thaw comes it runs straight into the melt-water and the ground, carrying disease into exactly the water a camp or a stricken population will be drinking. So waste is disposed of by the proper means that course teaches, sited well away from and below any water and any place where snow is gathered clean, and a member never gathers snow for water from ground that anyone has fouled. The cold and the wish to get back into shelter are no excuse; keeping the clean strictly apart from the dirty matters, if anything, more in winter, because a stricken population crowded in the cold, short of clean water and weakened by exposure, is exactly the population among which a water-borne illness does the most harm.

In Practice: A Warm Drink at the Doorway

On a winter welfare round in a harbour district you find a woman huddled in a shop doorway, awake and shivering and clearly chilled to the bone but talking with you clearly and steadily. You have a flask of warm, sweetened tea, and this lesson tells you it is exactly the right thing to offer her, for it is fuel and comfort at once, a little warmth from the inside and a little water and sugar to a body that has had neither for hours. Because she is fully conscious and able to hold the cup and drink for herself, you give it to her and sit with her while she takes it in small sips. You think, too, of your own flask, half emptied across a long shift, and remember that you have not drunk nearly enough yourself, though you have not once felt thirsty; you drank at the last halt only because your section commander called it, and you make yourself drink again now. You notice the woman's feet are soaked through, and you know from the foot drill that wet, cold feet are the start of a real injury, not a small discomfort, so you flag it as something to be put right and not left. What you do for her beyond this, and the warning that a drowsy or barely rousable person must never be given anything to drink, belong to the welfare and first-aid lessons; that a warm, sweet drink is the right help for a cold but wakeful person, and that you must keep yourself watered and your own feet sound too, belongs to this one.

Check Your Understanding

1. Explain why a member can become dangerously dehydrated in the cold without ever feeling thirsty, naming the routes by which water is lost, and describe the habit and the plan that prevent it. By what readily available sign can a member judge whether they are drinking enough, and what does that sign look like when they are not?
2. Why should snow and ice be melted and warmed before drinking rather than eaten, and what are the steps of melting it well? Once melted, how should a member treat the water, and why does the cold change how purification tablets are used?
3. Why does a member need to eat more in the cold, and what kinds of food does the winter diet lean on and why? Explain why the care of the feet and the rationing of fuel are both treated in this lesson as defences against the cold rather than mere housekeeping.

Reflection (write a short paragraph): This lesson argues that the simplest defences against the cold, drinking, eating, and keeping dry, are the ones most easily neglected on a hard task, and that the cold punishes that neglect more than warmer weather would. Think about a long winter shift on the welfare operation, and about a vulnerable person you might be sent to help. Which of these small disciplines, drinking to a plan, eating hot and often, sparing the fuel, or the daily care of your feet, do you think you would be most likely to let slide in yourself, and how might letting it slide turn a capable member into a casualty, and so leave the person you were sent to help without you?

Summary

• In the cold the body loses water steadily through the breath, through unfelt sweat, and as urine (cold diuresis), but the thirst that would warn a member in summer is dulled, so dehydration can creep up unnoticed; it saps strength, will, and judgement and worsens cold injury by slowing warm blood to the extremities, and the defence is to drink regularly to a plan whether or not you feel thirsty, using the colour of the urine, pale and plentiful for enough, scant and dark for too little, as a guide, and never alcohol.
• Running water is the first choice; where snow or ice must be used it should be gathered clean and dense, melted in a pot started with a little water so it does not scorch, warmed, and then treated as doubtful water by the boiling, tablets, or filtration of the Field Health, Hygiene, and Sanitation course, never eaten, because eating snow costs the body precious heat and gives little water and can injure the mouth.
• Water must be kept from freezing by filling the bottle warm, carrying it close to the body and off the ground, and leaving room to shake it; melt extra water at night ready for the morning.
• The body burns far more fuel to make heat in the cold, so a member must eat more, eat often, and lean on fats and carbohydrates, and keep eating when appetite is low; regular hot food and warm drinks are a real defence against the cold and a lift to morale, and a meal before sleep helps a member stay warm through the night.
• Fuel for melting and cooking is rationed and managed for the whole task, using a lid, shelter from the wind, dense snow, and batch heating, because the member who runs out of fuel runs out of water and hot food together.
• Winter hygiene is harder but still vital to prevent illness: keep up hand-washing and the strip wash in shelter and warmed water, and above all keep the daily foot drill of Lesson 02 and the Field Health course, dry feet, dry socks changed at every chance, daily inspection, and never sleeping in wet socks, to prevent the non-freezing cold injury of Lesson 01; and dispose of waste properly and well away from water even when the ground is frozen.

Crown Copyright © 2026 | Published by Authority of H.R.H. The Prince of Kaharagia