Get answers to the top questions about how to protect your employees against the dangers of cold stress when the temperature drops, including warm-up schedules and survival strategies.
Q: What is cold stress?
A: According to the National Institute for Occupational Safety and Health (NIOSH), what constitutes cold stress and its effects can vary across different areas of the country. In regions relatively unaccustomed to winter weather, near freezing temperatures are considered factors for cold stress. Whenever temperatures drop decidedly below normal and as wind speed increases, heat can more rapidly leave your body. These weather_related conditions may lead to serious health problems such as frostbite or hypothermia. Anyone exposed to extreme cold or who works in cold environments may be at risk of cold stress.
Q: What’s the coldest temperature ever recorded?
A: Antarctica holds the record. There’s the official record, as recognized by the World Meteorological Organization (WMO), of —128.6 F recorded on July 21, 1983, and the unofficial record of —135.8 F recorded on July 31, 2010. The WMO record was measured with a thermometer, while the unofficial record was documented using satellite measurements. Closer to home, according to the National Oceanic and Atmospheric Administration (NOAA), the coldest temperature recorded in the U.S. was —80 F in Prospect Creek, Alaska on Jan. 23, 1971. In the contiguous U.S., Roger Pass, Montana holds the record at —70 F recorded on Jan. 20, 1954.
Q: Does the Occupational Safety and Health Administration (OSHA) have a regulation specific to protecting workers from extreme cold temperatures?
A: No. OSHA does not have a specific standard that covers working in cold environments but under the General Duty Clause, Section 5(a)(1) of the Occupational Safety and Health (OSH) Act of 1970, employers have a responsibility to protect workers from recognized hazards that are causing or likely to cause death or serious physical harm to their employees.
Q: Are employers responsible for paying for cold weather clothing for their employees?
A: No, with one exception. OSHA’s final rule for Employer Payment for Personal Protective Equipment became effective on Feb. 13, 2008 and the compliance deadline was May 15, 2008. OSHA Instruction / Compliance Directive CPL- 02_01_050 Enforcement Guidance for Personal Protective Equipment in General Industry became effective Feb. 10, 2011. It instructs OSHA enforcement personnel on both the agency’s interpretations of the standards and the procedures for enforcing them. The directive states “employers are not required to pay for ordinary clothing, skin creams, or other items used solely for protection from weather such as winter coats, jackets, gloves, and parkas that employees would normally have to protect themselves from the elements.” The guidance calls out the exception to this rule with the following enforcement: “NOTE: In the rare case that ordinary weather gear is not sufficient to protect the employee and special equipment or extraordinary clothing is needed to protect the employee from unusually severe weather conditions, the employer is required to pay for such protection. Clothing used in artificially controlled environments with extreme hot or cold temperatures, such as freezers, is not considered part of the weather gear exception.”
Q: More specifically, what are the employer’s responsibilities when it comes to protecting employees working in the cold?
A: The OSHA Winter Weather — Plan. Equip. Train. resource page offers the following guidance for employers who have employees working in cold environments. Employers should train workers. Training should include:
Employers should:
Q: Does OSHA offer any guidelines regarding the type of clothing that should be used in cold environments?
A: In its Cold Stress Safety and Health Guide, OSHA offers the following guidance:
Dressing properly is extremely important to preventing cold stress. The type of fabric worn also makes a difference. Cotton loses its insulation value when it becomes wet. Wool, silk and most synthetics, on the other hand, retain their insulation even when wet. The following are recommendations for working in cold environments:
Q: What is wind chill?
A: Even relatively mild winds can greatly exacerbate the impact of cold temperatures. Wind chill is the term used to describe the rate of heat loss from the human body, resulting from the combined effect of low air temperature and wind speed. The wind chill temperature is a single value that takes both air temperature and wind speed into account. For example, when the air temperature is 40 F and the wind speed is 35 mph, the wind chill temperature is 28 F; this measurement is the actual effect of the environmental cold on the exposed skin.
The National Weather Service’s Wind Chill Chart (below) shows the impact winds of various speeds have on the real-world temperatures. If the temperature reading is 15 F with a 20 mph wind, the real-world feel is —2 F. The chart also indicates approximately when frostbite would set in based on the calculated wind chill temperatures.
Q: How cold is too cold to work outside?
A: There’s no exact answer to this question. Some jobs must be conducted regardless of how low the temperatures drop. Employers must use engineering (radiant heaters, wind screens, etc.) and administrative (job rotation, increased warming breaks, etc.) control measures to help limit worker exposure in extreme situations.
The American Conference of Governmental Industrial Hygienists (ACGIH) has developed a Work/Warm-Up Schedule for a four hour shift that takes both air temperature and wind speed into account. The schedule was adapted from the ACGIH 2012 Threshold Limit Values (TLVs). It provides recommendations on scheduling work breaks and ceasing non-emergency work. Here's an example schedule:
| Air Temperature -- Sunny Sky | No Noticeable Wind | 5 mph Wind | 10 mph Wind | 15 mph Wind | 20 mph Wind | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| °C (approx.) | °F (approx.) | Max. Work Period | Number of Breaks | Max. Work Period | Number of Breaks | Max. Work Period | Number of Breaks | Maximum Work Period | Number of Breaks | Maximum Work Period | Number of Breaks |
| –26 to –28 | –15 to –19 | (Normal Breaks ) 1 | (Normal Breaks ) 1 | 75 min | 2 | 55 min | 3 | 40 min | 4 | ||
| –29 to –31 | –20 to –24 | (Normal Breaks ) 1 | 75 min | 2 | 55 min | 3 | 40 min | 4 | 30 min | 5 | |
| –32 to –34 | –25 to –29 | 75 min | 2 | 55 min | 3 | 40 min | 4 | 30 min | 5 | Non-emergency work should cease | |
| –35 to –37 | –30 to –34 | 55 min | 3 | 40 min | 4 | 30 min | 5 | Non-emergency work should cease | |||
| –38 to –39 | –35 to –39 | 40 min | 4 | 30 min | 5 | Non-emergency work should cease | |||||
| –40 to –42 | –40 to –44 | 30 min | 5 | Non-emergency work should cease | |||||||
| –43 & below | –45 & below | Non-emergency work should cease | |||||||||
Q: What is hypothermia and what is the recommended treatment?
A: According to OSHA’s Cold Stress Safety and Health Guide, hypothermia occurs when body heat is lost faster than it can be replaced and the normal body temperature (98.6 F) drops to less than 95 F. Hypothermia is most likely at very cold temperatures, but it can occur even at cool temperatures (above 40 F) if a person becomes chilled from rain, sweat or submersion in cold water.
Q: What are the symptoms of hypothermia?
A: Mild symptoms:
Moderate to severe symptoms:
Q: What can be done for a person suffering from hypothermia?
A: Here's what you can do for someone suffering from hypothermia:
Q: What is frostbite and what is the recommended treatment?
A: According to OSHA’s Cold Stress Safety and Health Guide, frostbite is an injury to the body that is caused by freezing of the skin and underlying tissues. The lower the temperature, the more quickly frostbite will occur. Frostbite typically affects the extremities, particularly the feet and hands. Amputation may be required in severe cases.
Q: What are the symptoms of frostbite?
Q: What can be done for a person suffering from frostbite?
Q: Why is cold water immersion particularly deadly?
A: According to the NIOSH Cold Stress Resource Page, cold water immersion creates a specific condition known as immersion hypothermia. It develops much more quickly than standard hypothermia because water conducts heat away from the body 25 times faster than air. While people in temperate climates typically don’t consider themselves at risk from hypothermia in the water, hypothermia can occur in any water temperature below 70 F. Survival times can be lengthened by wearing proper clothing (wool, silk and synthetics; not cotton); using a personal flotation device (PFD), life vest, immersion suit, or dry suit; having a means of both signaling rescuers (strobe lights, personal locator beacon, whistles or flares); and having a means of being retrieved from the water.
Q: What about traveling in extreme cold conditions?
A: The Centers for Disease Control and Prevention (CDC) Winter Weather Resource Page offers some suggestions regarding preparing a vehicle for winter travel. In addition to performing all of the vehicle manufacturer’s recommended maintenance, the CDC suggests that each fall vehicle owners do the following:
During the winter months, keep the gas tank near full to help avoid ice in the tank and fuel lines.
Q: What should I do if I become stranded in my vehicle during a winter storm?
A: The CDC suggests the following items be part of a winter survival kit for a vehicle:
Should you find yourself stranded, the CDC advises you do the following:
CDC’s Extreme Cold: A Prevention Guide to Promote Your Personal Health and Safety
The NIOSH Cold Stress Resource Page
OSHA’s Winter Weather Resource Page: Plan. Equip. Train. Resource Page
OSHA’s Cold Stress Safety and Health Guide
National Weather Service - National Oceanic and Atmospheric Administration
OSHA Instruction/Compliance Directive CPL 02-01-050
The information contained in this article is intended for general information purposes only and is based on information available as of the initial date of publication. No representation is made that the information or references are complete or remain current. This article is not a substitute for review of current applicable government regulations, industry standards, or other standards specific to your business and/or activities and should not be construed as legal advice or opinion. Readers with specific questions should refer to the applicable standards or consult with an attorney.