1. Working in Cold Conditions
Cold Weather
Working in Cold Conditions
Speaker’s Notes:
Working in cold conditions, whether exposed to cold and windy conditions outside or inside refrigerated environments, can result in cold-related illnesses and injuries such as hypothermia or frostbite.
Cold-related illnesses and injuries can lead to permanent tissue damage and even death.
Although our bodies have some natural heating systems, they are not designed to stay warm in extremely cold conditions. Protective clothing and work practices are required to keep workers protected in cold conditions.
In this training session we will discuss signs and symptoms of cold-related illnesses and injuries, first aid measures, protective clothing, and safe work practices for cold conditions.

2. Cold Workplaces Roofs in cold weather
Bridges near large bodies of water
High buildings exposed to wind
Refrigerated rooms or containers
Commercial fishing areas
Steel structures that retain cold
Unheated warehouses in cold climates
Background for the Trainer:
Have employees discuss other jobs in which they have been exposed to cold conditions.
Speaker's Notes:
There are a number of workplaces and work environments where workers can be exposed to cold conditions.
Construction workers are exposed to cold conditions in environments such as roof work in cold weather.
Working on bridges near large bodies of water exposes workers to both the cold temperature and cold wind.
Working outside of high rise buildings can expose workers to cold temperatures and cold winds.
Refrigerated rooms, containers, or vessels expose workers to controlled cold environments. These environments will typically not have a wind chill factor.
Commercial fishermen are exposed to cold weather, cold winds, and cold water.
Steel structures retain cold temperatures and transfer the cold easily to the worker’s body.
Warehouses in colder climates are usually not heated in the winter, so workers are exposed to cold temperatures.

3. Goals Cold-Related Illnesses and injuries and first aid Treatment
Risk Factors and Prevention Measures
Quiz
Speaker’s Notes:
First, we will discuss the different types of cold-related illnesses and injuries, their symptoms, and first aid for those disorders.
Next, we will discuss how to prevent cold-related disorders by understanding who might be susceptible and what measures we can take to keep our bodies warm and safe.
Finally, we will wrap up this session with a short quiz.

4. Body reacts to cold by: Trying to maintain core temperature of 98.6ºF
Decreasing blood flow to extremities to prevent heat loss which
Keeps internal organs warm
Increases chance of frostbite
Shivering generates heat
Speaker’s Notes:
Let’s talk about how our bodies attempt to cope with exposure to cold temperatures so we can better understand cold-related disorders.
The body tries to maintain an internal core temperature of about 98.6ºF.
In cold conditions the body will decrease blood flow to skin and extremities such as arms and legs. This minimizes cooling of the blood by exposure to the outside cold temperatures.
Internal organs are kept warmer because of the increased blood flow to the internal organs.
The reduced blood flow to the extremities increases the chance of frostbite.
Shivering is another response that the body will use to generate heat. Shivering increases the body’s metabolic rate. Maximum severe shivering develops when the body temperature has fallen to 95ºF.

5. Hypothermia Progressive loss of body heat
Accelerated when person is wet
Most cases occur in air temperatures between 30ºF and 50ºF
Can occur in air temperatures as high as 65ºF
Occurs in water at 72ºF
Background for the Trainer:
Discuss any incidents of hypothermia that your workers may have experienced.
Speaker’s Notes:
Hypothermia is the progressive loss of body heat with prolonged exposure to cold.
Hypothermia is accelerated when a person is wet because of sweat or working in a damp environment.
Most cases of hypothermia occur in air temperatures between 30F and 50F.
Significant hypothermia can occur in air temperatures as high as 65F. It does not have to be extremely cold for a person to suffer from hypothermia. Other risk factors can contribute in warmer temperatures including wet clothing, lack of clothing, drugs or alcohol, and age.
Hypothermia can occur in water that is as warm as 72F.

6. Mild Hypothermia Shivering and chattering teeth Blue lips and fingers
Poor coordination
Background for the Trainer:
Discuss any incidents of mild hypothermia that may have occurred at your company.
Speaker’s Notes:
It is important to know the early signs and symptoms of hypothermia. If mild hypothermia goes unnoticed and the person is not treated, more serious hypothermia may occur and result in more dangerous health concerns.
Persistent shivering usually starts early, when core body temperature drops only a few degrees to 95F. The victim will shiver uncontrollably all over the body.
The victim will have blue lips and fingers. This is a sign that the blood flow has been restricted to the extremities.
Poor coordination can impact safety and increase risk from other workplace hazards.

7. Moderate Hypothermia Mental impairment and confusion
Disorientation and poor decision making
Inability to take precautions from the cold
Slower heart rate and breathing rate
Slurred speech
Background for the Trainer:
Discuss any incidents of moderate hypothermia that have occurred at your company.
Speaker’s Notes:
As hypothermia progresses from mild to moderate, victims lose the ability to understand that they are suffering symptoms from overexposure to the cold and should take corrective measures. When working alone, the chance of getting the necessary help is greatly decreased.
Victims begin to suffer from mental impairment and confusion and may even think they are actually getting warmer.
Victims may become disoriented and start to make poor decisions.
They may not think anything is wrong and decide not to seek shelter and get warm or may become disoriented and unable to find shelter.
Heart rate and breathing rate slow down, which decreases flow of blood and oxygen to internal organs, resulting in mental impairment. Victims become weaker and more lethargic.
Another obvious sign is slurred speech. Victims begin to lose some basic motor control and speech is affected.

8. Severe Hypothermia Resembles death Unconsciousness
Irregular or hard-to-find pulse
No shivering
No detectable breathing
Background for the Trainer:
Discuss any incidents of severe hypothermia that may have occurred at your company.
Speaker’s Notes:
Severe hypothermia resembles death; however, patients must be treated as if they are alive.
The victim may be unconscious.
The heart rate has slowed down to the point where the pulse is either irregular or difficult to find.
The victim is no longer shivering.
There is no detectable breathing.

9. First Aid for Hypothermia
Move victim to shelter
Remove wet clothing and wrap victim in warm covers
Apply direct body heat
Re-warm neck, chest, abdomen, and groin first
Give warm, sweet drinks if conscious
Monitor breathing, administer CPR
Get medical help
Speaker’s Notes:
First aid treatment for a victim of hypothermia involves stopping the cooling process and providing heat to begin re-warming the victim.
Get the victim out of the cold environment and away from the cold. Move the victim to a warm shelter.
Remove the victim’s wet and cold clothing and wrap the victim in warm, dry, and loose covers.
Apply direct body heat to the victim. Do not place the victim in front of a hot fire or stove. Do not apply heated blankets or pads. The best method of re-warming is to provide direct body-to-body heat.
Re-warm the internal organs first including the neck, chest, abdomen, and groin areas. Then re-warm the extremities.
Keep the victim awake and provide warm, sweet drinks if conscious. Do not give alcohol or caffeine drinks.
If the victim is unconscious, monitor the breathing and heart rate and administer CPR if needed.
Get medical help for all cases of hypothermia.

10. Frostbite Exposure to severe cold or contact with cold objects
Affects fingers, toes, cheeks, nose, and ears
Tissue freezes at 30ºF
May cause gangrene
More susceptible to future frostbite
Tissue death—amputation or loss of function
Background for the Trainer:
Discuss any incidents of frostbite that may have occurred at your company.
Speaker’s Notes:
Frostbite is a common injury that is caused by exposure to severe cold or contact with extremely cold objects. Frostbite occurs more readily from touching cold metal objects than from exposure to cold air because heat is rapidly transferred from skin to metal.
The body parts most commonly affected by frostbite are fingers, toes, cheeks, nose, and ears.
Frostbite occurs when skin tissue actually freezes—cells and blood vessels are damaged. The freezing point of skin is approximately 30ºF. Wind chill can be a significant factor in accelerating the process.
The reduced blood flow from damaged blood vessels can cause gangrene.
Body parts that have suffered frostbite damage are more susceptible to suffering frostbite in the future.
Severe frostbite may result in tissue death, which often requires amputation or results in loss of function.

11. Frostbite Symptoms Sensations of coldness
Tingling, stinging, or aching sensation
Skin feels numb and cold to the touch
Skin is waxy and appears white
Blistering, turning red, then black
Speaker’s Notes:
Frostbite symptoms vary and are not always painful. Sometimes victims may not even know they are suffering frostbite.
Usually frostbite starts with uncomfortable sensations of coldness.
Then the victim may feel tingling, stinging, or aching sensations in the areas affected by frostbite.
The affected part of the body will feel numb and very cold to the touch.
Initially, the skin will be waxy and appear almost white.
In severe cases, this will be followed by heat, redness, swelling, blistering, and a color change to red and then black. Blistering usually takes about 10 days to subside.

12. First Aid for Frostbite
Warm gradually with body heat
Do not rub—may result in more tissue damage
Use water between 102°F-110°F
Apply sterile dressing to blisters
Do not thaw if risk of re-freezing
Get medical attention; thaw at hospital
Speaker’s Notes:
Warm frostbitten areas gradually with body heat. Do not put affected body part near a stove or other source of heat. Do not pour hot water onto the area.
Do not rub the frostbitten area because this can lead to greater tissue damage.
Water between 102ºF and 110ºF can be used to warm up the affected area.
Apply sterile dressing to blistered areas. Keep the blisters clean and dry and do not break.
Do not thaw frozen tissue that has suffered severe frostbite unless you are far from medical aid and there is no risk of re-freezing.
Get medical attention for more severe cases and let hospital personnel thaw the frozen tissue, especially if the affected tissue involves the hands or feet.

13. Goals Cold-Related Illnesses and injuries and first aid Treatment
Risk Factors and Prevention Measures
Quiz
Speaker's Notes:
Are there any questions regarding the different types of cold-related illnesses and injuries, their symptoms, and first aid for those disorders?
Now we will discuss how to prevent cold-related disorders by understanding who might be more susceptible and what measures we can take to keep our bodies warm and safe.

14. Environmental Cold Stress Factors
Low temperature
Cool, high winds
Dampness
Cold water
Speaker's Notes:
Obviously, temperature plays a key role in determining the amount of stress that a worker faces in a cold work environment. The colder the temperature, the greater the cold-related stress—which means a higher risk for cold-related disorders.
Cool winds also contribute to cold stress. Wind chill may often contribute to cold-related illnesses and injuries without workers knowing what hit them.
Working in damp conditions, or working and sweating in cold conditions, will also contribute to cold-related disorders. It is important to always stay dry.
Cold water may result in hypothermia much quicker than the cold air.

15. Wind Chill Temperatures
Combined effect of air temperature and air movement
Background for the Trainer:
The information for this chart was taken from the new wind chill chart developed by the National Weather Service.
Speaker's Notes:
Wind chill is the combined effect of air temperature and air movement.
A dangerous situation of rapid heat loss may arise for any workers exposed to a combination of high winds and cold temperatures.
In this chart, we can see how the “wind chill temperature” drops as the speed of the wind picks up. The National Weather Service also determined when the combination of temperature, wind speed, and exposure time will produce frostbite on humans.
The teal numbers indicate that a person’s skin can be exposed for 30 minutes before frostbite develops.
The blue numbers indicate that a person’s skin can be exposed for 10 minutes before frostbite develops.
The purple numbers indicate that a person’s skin can be exposed for 5 minutes before frostbite develops.
When in the field, it may be difficult to gauge wind speed. Some ways to estimate speed in the field include:
5 mph – light flag just moves
10 mph – light flag is fully extended by wind
15 mph – newspaper sheet is raised off the ground
20 mph – wind capable of blowing snow

16. Other Risk Factors Inadequate or wet clothing
Drug use or certain medications
A cold or certain diseases
Male gender
Age
Heart condition
Physical condition
Background for the Trainer:
Your company may require employees to meet certain physical conditions before they can work in cold environments. If so, describe them.
Speaker's Notes:
In addition to cold temperatures and windy conditions, there are other risk factors that can contribute to cold-related illnesses and injuries.
Inadequate or wet clothing increases the risk because the actual effects of cold on the body depend on how well the skin is insulated from cold temperatures and cold wind. Wet or damp clothing does not provide sufficient insulation from cold temperatures.
Drug use or certain medications can inhibit the body’s response to the cold or even impair judgment such that the victim does not realize he or she is suffering symptoms of a cold-related disorder. Avoid drugs, alcohol, caffeine, and cigarettes when working in cold conditions.
Certain diseases or medical conditions such as a cold, heart disease, asthma, bronchitis, diabetes, atherosclerosis, hypothyroidism, and even poor blood circulation may increase risk of suffering a cold-related illness or injury. Be sure to have a physical evaluation by a medical doctor prior to doing work in cold conditions.
Male death rates in cold conditions are greater than female death rates. Some suspected reasons include inherent risk-taking activities, body fat composition, or other physiological differences.
Workers become more susceptible to cold-related illnesses and injuries as they age.
Exertion in cold can constrict blood vessels in the heart. This means older workers or workers with coronary disease have an increased risk of heart attack when working in cold conditions.
People who are overweight, have had inadequate rest, or are just physically unfit are more susceptible to cold-related illness.

17. Environmental Protection
Heated shelters
Windscreens
On-site sources of heat
Thermally insulated tools and work surfaces
Background for the Trainer:
Discuss the specific engineering controls used by your company. Consider bringing in pictures of your engineering controls.
Speaker's Notes:
Now that we know the conditions that increase the risk of workers suffering a cold-related disorder, we need to learn how to take steps to protect those workers.
When protecting workers from cold conditions, it is important to start with engineering controls, then use administrative controls, and finally, personal protective equipment (PPE). Do not rely solely on PPE.
Heated shelters should be provided for workers who experience prolonged exposure to equivalent wind chill temperatures of 20F or less. Workers entering the shelter should remove their outer layer of clothing and loosen other clothing to let sweat evaporate. In some cases, a change of clothing may be needed.
Workers that show signs of shivering, frostbite, fatigue, drowsiness, irritability, or euphoria should immediately return to the heated shelter.
Windscreens should be erected around the work areas to protect workers from drafty or windy conditions.
Utilize on-site sources of heat to protect hands, feet, and face from frostbite. Use air jets, radiant heaters, or contact warm plates.
Use tools and equipment that have thermal insulating materials on the handles. Provide thermally insulated work surfaces so the workers do not have to sit or kneel on cold surfaces.

18. Administrative Controls
Work and Warm-up Schedule for 4-hour Shift
Background for the Trainer:
Discuss the specific administrative controls utilized by your company.
Speaker's Notes:
Administrative controls for cold conditions include limiting worker exposure to the cold conditions by providing additional breaks or by rotating workers through the cold conditions.
Use this table to determine maximum working periods and the number of breaks workers should have for each 4-hour work period. Between the 4-hour shifts, workers should be given an extended lunch period in a warm location.
This schedule applies to workers doing moderate to heavy work. Workers doing light to moderate work should be given one additional break during the 4-hour shift.
Workers should be given 10-minute breaks in a warm location.
This work schedule applies to workers in dry clothing. When clothing gets wet, workers should immediately retreat to the warm shelter and change clothing.

19. Protective Clothing Several layers of clothing
Synthetic fibers next to skin to whisk away sweat
Water-repellent, wind- resistant outer clothing
Hats, hoods, or face covers
Insulated, waterproof footgear
Insulated, waterproof gloves
Change of clothing available
Background for the Trainer:
Bring samples or pictures of, or describe, the protective clothing that your company provides workers exposed to cold conditions.
Speaker's Notes:
Wear several layers of clothing rather than one thick layer. Air captured between the layers acts as an insulator.
Wear synthetic fibers such as polypropylene next to the skin because these whisk away sweat so it does not stay against your skin and allow for ventilation.
If conditions are wet or windy, wear appropriate outer clothing that protects from the wetness and the wind, but still allows some ventilation. Gortex or nylon materials are often used.
Workers should wear hats, hoods, or face covers to prevent heat loss from the head and to protect ears from the cold. Up to 40 percent of body heat can be lost when the head is exposed.
Wear insulated footgear that protects against the cold and dampness. Footgear should not be too tight because it will restrict blood flow and contribute to the potential for frostbite. Footgear should be large enough to allow wearing either one thick sock or two thin pairs of socks. Wearing too many socks can tighten the fit and do more harm than good.
Wear insulated gloves that protect against the cold and dampness. Gloves should not be so tight that they restrict movement and blood flow in the hands. Fingers and hands lose their dexterity at temperatures below 59F. If dexterity is required to do the job so that gloves cannot be worn, then appropriate engineering controls must be used.
Keep an extra change of clothing available in case work clothing becomes wet. When working in temperatures 35F or below, workers should immediately change clothes and be treated for hypothermia if their clothing gets wet.

20. Hand Protection Wear gloves when fine manual dexterity is not required
Use tools and machine controls designed for gloved hand operation
Limit bare hand work to minutes when < 60ºF
Use warm air jets, radiant heaters, contact warm plates
Use metal handles covered by thermal insulating material
Prevent contact frostbite when near metal surfaces < 20ºF
Speaker's Notes:
When fine manual dexterity is not required, wear gloves. When doing sedentary work, put on gloves in temperatures <60F. When the work is light, put on gloves in temperatures <40F. When the work is moderate, put on gloves in temperatures <20F.
Tools and machine controls for use in cold conditions should be designed for use by bulky gloved hand operation.
If working in temperatures <60F, limit bare hand work to minutes. Prolonged work will result in a loss of hand dexterity and control.
To continue doing bare hand work in cold conditions, use special measures such as warm air jets, radiant heaters, or contact warm plates.
Metal handles of tools or machine controls that are used in cold conditions should be covered by a thermal insulating material.
Prevent contact frostbite when working near metal surfaces that are <20F by wearing insulated gloves and warning workers to avoid skin contact with the cold surfaces.

21. Other Protective Controls
Be medically fit
Eat high calorie foods
Consume warm, sweet drinks and soups
Avoid coffee
Stay in good physical condition
Speaker’s Notes:
Workers should be medically fit to work in extremely cold conditions, especially workers that have a tendency to the risk factors already mentioned, such as heart conditions, diabetes, etc. Employers should consider implementing a medical surveillance program.
Workers should eat high calorie foods when working in cold conditions.
Workers should consume warm, sweet drinks and soups while at the worksite to maintain calorie intake and fluid volume.
Avoid coffee because it increases water loss and blood flow to extremities.
Stay in good physical condition through regular exercise, plenty of sleep, and a balanced diet.

22. Safe Work Practices Avoid heavy perspiration
Work in the warmest hours of the day
Minimize prolonged sitting, standing
Allow time to adjust to cold
Do not work alone
Watch for symptoms of cold-related illness
Background for the Trainer:
Discuss any other safe work practices utilized by your company.
Speaker’s Notes:
Avoid activities, whenever possible, that can lead to heavy perspiration.
When possible, schedule work for the warmest period of the day.
Minimize activities that reduce circulation, such as sitting or standing in cold environments for prolonged periods of time.
Allow a period of adjustment to the cold before starting on a full work schedule.
Never work alone in very cold weather—use the buddy system.
Watch for symptoms of cold-related illness—seek shelter and first aid immediately.

23. Goals Cold-Related Illnesses and injuries and first aid Treatment
Risk Factors and Prevention Measures
Quiz
Speaker’s Notes:
Are there any questions on the risk factors associated with cold-related illnesses and injuries or the prevention measures that we can take to stay warm and safe?
Let’s wrap up this session with a short quiz.

24. Summary Symptoms of hypothermia and frostbite First aid treatment
Wind chill factor
Engineering and administrative controls
Protective clothing and staying dry

25. Quiz
1. The body responds to cold by shivering and _____________________________________
2. Hypothermia can occur in air temperatures as high as 65ºF. True or False
3. Describe at least three symptoms of hypothermia.
4. Describe at least one form of environmental protection for workers in the field.
5. Other risk factors of cold-related illness include: certain medication, certain diseases, age, and physical condition. True or False

26. Quiz (cont.)
6. Drinking coffee will help workers stay warm. True or False
7. Describe at least three symptoms of frostbite.
8. Warm up frostbitten areas by rubbing gently. True or False
9. Environmental cold stress factors include: temperature, wind, and __________________
10. Administrative controls, such as __________, can be used to protect workers from overexposure to cold conditions

27. Quiz Answers 1. Decreasing blood flow to the extremities
2. True, when other contributing factors are present
3. Confusion, disorientation, slow heart rate and breathing, shivering, blue lips, poor coordination, slurred speech
4. Heated shelters, windscreens, heat sources, thermal insulated tools
5. True

28. Quiz Answers (cont.)
6. False, coffee increases blood flow to the extremities
7. Cold sensation, tingling, aching, numbness, white skin, waxy skin
8. False, rubbing will contribute to the skin damage
9. Dampness
10. Limiting work time or taking additional breaks