Working in Heat and Cold

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When working in either excess heat or cold, injury or illness can happen. In both heat and cold, the workers may not notice the effects, putting them at greater risk. Workers are exposed to heat when they work outdoors in the summer, or inside hot environments such as kitchens, boiler plants or around hot equipment. Workers are exposed to cold when they perform work outside in the winter or in cold storage areas.

Employer duties

Employers have a duty to take every reasonable precaution to protect the occupational health and safety of persons at or near the workplace.

General requirements

There are general requirements to keep a workspace at adequate heat, including:

  • Toilet facilities
  • Chemical toilets or privies in cold weather
  • Lunch and rest rooms
  • First aid room

Adequate heat would include maintaining a minimum temperature of an enclosed workplace, as based on the nature of the work performed in that space as shown in Table 1. The relative humidity of an office environment must be 30%, at minimum.

Table 1: Nature of the work and minimum temperature required

Nature of work performed Minimum temperature required (°C)
Light work performed while sitting; any mental work, precision work, reading or writing 20
Light physical work performed while sitting; electric machine sewing and work with small machine tools 19
Light work performed while standing; machine tool work 17
Moderate work performed while standing; assembly and trimming 16
Heavy work performed while standing, drilling and manual work with heavy tools 12

There are situations where these temperatures do not apply, including:

  • A workplace that is normally unheated.
  • When the need to open doors makes heating the area impractical.
  • Where perishable goods are processed or stored, and the goods require a lower temperature.
  • Where radiant heating provides heat to the same temperature.
  • When the process or activity being done would be uncomfortable at the temperature specified.

Temporary heat is not appropriate within a confined space.

Working in Extremes of Temperature

In PEI, the allowable exposures to heat and cold must follow the Threshold Limit Values (TLVs) set by the American Conference of Governmental Industrial Hygienists (ACGIH).


"Heat stress" is defined as the "net [overall] heat load to which a worker may be exposed from the combined contributions of metabolic heat, environmental factors (i.e., air temperature, humidity, air movement, and radiant heat), and clothing requirements. Mild or moderate heat stress may cause discomfort and may adversely affect performance and safety, but it is not harmful to health. As the heat stress approaches human tolerance limits, the risk of heat-related disorders increases." ACGIH proposes a work/rest schedule, based on the physical activity level, and whether the individual is acclimatized to the heat. Acclimatization is the term given to the development of resistance to, or tolerance for, an environmental change. Although people can often adapt to hot environments, they do not acclimatize well to cold.

Health problems can arise when the air temperature or humidity rises above the range for comfort, ultimately affecting the worker’s performance.

Symptoms of heat exhaustion may start suddenly, and include:

  • Nausea or irritability.
  • Dizziness.
  • Muscle cramps or weakness.
  • Feeling faint.
  • Headache.
  • Fatigue.
  • Thirst.
  • Heavy sweating.
  • High body temperature.

Workplaces can implement controls, including:

  • Mechanizing tasks to reduce physical exertion
  • Reducing humidity, where possible
  • Adjusting hours of work to cooler times
  • Allowing workers time to acclimatize before completing a full workload
  • Use frequent rest breaks or allow workers to set their own pace of work
  • Provide cool rest areas, such as the cab of a vehicle or a shade structure
  • Provide cool drinking water
  • Train workers how to recognize symptoms of heat exposure in themselves and others
  • Train first aid responders in heat exposure first aid measures

First aid for heat exhaustion includes:

  • Get medical aid. Stay with the person until help arrives.
  • Move to a cooler, shaded location.
  • Remove as many clothes as possible (including socks and shoes).
  • Apply cool, wet cloths or ice to the head, face, or neck. Spray with cool water.
  • Encourage the person to drink water, clear juice, or a sports drink.


Cold challenges the body in three ways (temperature, wind, and wetness). Depending on the severity of cold conditions, heat loss can occur. Uncomfortably cold working conditions can lead to lower work efficiency and higher incident rates. Cold impairs the performance of complex mental tasks. Manual tasks are also impaired because the sensitivity and dexterity of fingers are reduced in the cold. At even lower temperatures, the cold affects the deeper muscles resulting in reduced muscular strength and stiffened joints.

Cooling of body parts may result in various cold injuries - with hypothermia being the most serious. Nonfreezing cold injuries include chillblain, immersion foot and trenchfoot. Freezing injuries include frostnip and frostbite. Exposure to cold weather, particularly in water-soaked clothing or from direct immersion (i.e., a fall overboard or into a hole in the ice) can result in dangerous overcooling of the body.

When a person is exposed to the cold, be aware of the following symptoms:

  • Skin may have redness, swelling, or tingling
  • Blisters and pain
  • Numbness
  • For frostbite, the skin may look waxy or feel colder than the area around it. In severe cases, there could be tissue damage without pain
  • As hypothermia occurs, the feeling of being cold and pain might diminish, and muscular weakness or drowsiness may be experienced. Shivering may stop. Loss of consciousness may occur

Workplaces can implement controls, including the following for work at or below -12°C:

  • constant observation (supervisor or buddy system)
  • adjusting the pace or rate of work so that it is not too high and cause heavy sweating that will result in wet clothing
  • provide time for new employees to become accustomed to the conditions
  • arranged in such a way that sitting and standing for long periods are minimized
  • training in safe work practices such as,
    • re-warming procedures,
    • proper clothing practices,
    • proper eating and drinking habits,
    • recognition of cold stress/frostbite, and
    • signs and symptoms of hypothermia or excessive cooling of the body (including when shivering does not occur)
TLVs are published in the Threshold Limit Values and Biological Exposure Indices for 2019, and as amended from time to time.
Reference: 2022 TLVs and BEIs: Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists, 2022. p.229
Chilblains  are a mild cold injury caused by prolonged and repeated exposure for several hours to air temperatures that are cold, but not freezing (from above freezing (0°C or 32°F) to as high as 16°C (or about 60°F)). In the affected skin area, there will be redness, swelling, tingling, blisters, and pain. Seek medical help if an infection occurs.
Immersion foot  occurs in individuals whose feet have been wet, but not freezing cold, for days or weeks. It can occur at temperatures up to 10°C (50°F). The primary injury is to nerve and muscle tissue. Symptoms include tingling and numbness; itching, pain, swelling of the legs, feet, or hands; or blisters may develop. The skin may be red initially and turn to blue or purple as the injury progresses. In severe cases, gangrene may develop.
Trenchfoot  is a "wet cold disease" resulting from prolonged exposure in a damp or wet environment from above the freezing point to about 10°C (50°F). Depending on the temperature, onset of symptoms may range from several hours to many days but the average is three days. Trenchfoot is more likely to occur at lower temperatures whereas an immersion foot is more likely to occur at higher temperatures and longer exposure times. A similar condition of the hands can occur if a person wears wet gloves for a prolonged period under cold conditions described above. Symptoms are similar to an immersion foot.

General Regulations


Section 2.2 Toilet facilities

2.2 Every employer shall at each workplace provide proper toilet facilities which shall be maintained and kept clean and shall have adequate provision for privacy, heat, light and ventilation.

Section 2.8 Requirements

2.8 Every employer shall ensure that all chemical toilets or privies are

(a) provided from the start of the project;

(b) constructed so that any user is sheltered from view and protected from weather and flying objects;

(c) adequately heated in cold weather;

(d) provided with adequate supplies of disinfectant;

(e) maintained in a clean and sanitary condition.


Section 4.1 Lunch and rest room

4.1 In every workplace the employer shall provide a clean lunch and rest room that

(a) does not have a door opening directly into a toilet facility;

(b) is separate from any place where there is the possibility of food being contaminated by a dangerous substance;

(c) is not used for any purpose that is incompatible with its use as a lunch room;

(d) is adequately provided with

(i) light, heat and ventilation,

(ii) hand cleansing and drying facilities in close proximity,

(iii) sufficient tables and seating facilities for the use of workers,

(iv) suitable covered receptacles for the disposal of food; and

(e) is kept in a sanitary condition.

[EC2021-126, s. 3]


Section 7.3 Portable heaters

7.3 The employer shall ensure that portable heaters are not

(a) used in a confined space;

(b) located in or adjacent to a means of egress.


Section 9.14 First aid room

9.14 (1) Where

(a) either

(i) the only work conducted at a workplace is work other than low risk work, or

(ii) both low risk work and work other than low risk work are conducted at a workplace; and

(b) there are more than 100 workers regularly employed on any one shift at the workplace,

the employer shall provide a first aid room at the workplace.

(2) An employer who is required under subsection (1) to provide a first aid room at a workplace shall ensure that the first aid room

(a) has adequate lighting, ventilation and heating;

(b) is kept clean and in a sanitary condition;

(c) is of adequate size to accommodate a stretcher;

(d) has posted emergency telephone numbers;

(e) is used only for the purpose of administering first aid;

(f) is accessible by the workers at all times during their shift; and

(g) is equipped with

(i) a telephone or other means of communication between the first aid room and the emergency medical services that will be transporting the worker, if applicable,

(ii) instructions on how and where to access a workplace first aider,

(iii) a permanently installed sink with hot and cold running water,

(iv) a bed or cot with a moisture-protected mattress and two pillows,

(v) a treatment chair with arm rests,

(vi) a flashlight,

(vii) a wash basin made from stainless steel or polypropylene,

(viii) a nail brush,

(ix) a package of paper towels,

(x) hand soap,

(xi) a package of disposable paper cups,

(xii) a kidney basin made of stainless steel or polypropylene, and

(xiii) a large Type 3 Intermediate First Aid Kit, that meets the requirements specified in subsection 9.11(4).

[EC2012-49, s. 1; EC2021-126, s. 18]


Section 11.9 Humidity

11.9 The employer shall ensure that the relative humidity in an office environment shall be a minimum of 30%.

Section 11.10 Temperature

11.10 The employer shall ensure that, subject to section 11.11, the temperature of an enclosed workplace corresponds with the following chart:


Light work performed while sitting: any mental work, precision work, reading or writing 20°C
Light physical work performed while sitting: electric machine sewing and work with small machine tools 19°C
Light work performed while standing: machine tool work 17°C
Moderate work performed while standing: assembly and trimming 16°C
Heavy work performed while standing: drilling and manual work with heavy tools 12°C

Section 11.11 Exceptions

11.11 The minimum temperature required by section 11.10 does not apply at a workplace

(a) that is normally unheated;

(b) where the necessity of opening doors makes the heating of the area to the temperature specified in section 11.10 impractical;

(c) where perishable goods requiring lower temperatures are processed or stored;

(d) where radiant heating is such that a worker working in the area has the degree of comfort that would result were the area heated to the same temperature specified in section 11.10;

(e) where the process or activity is such that the temperature specified in section 11.10 could cause discomfort.

[EC2021-126, s. 3]


Section 42.1 Standards

42.1 Permissible heat and cold exposure shall conform to Threshold Limit Values (TLVs) as laid down by the American Conference of Governmental Industrial Hygienists (ACGIH).

R.S.P.E.I. 1988, c. O-1.01

Section 12 Duties of employers

12. (1) An employer shall ensure

(a) that every reasonable precaution is taken to protect the occupational health and safety of persons at or near the workplace;

(b) that any item, device, material, equipment or machinery provided for the use of workers at a workplace is properly maintained, and is properly equipped with the safety features or devices, as recommended by the manufacturer or required by the regulations;

(c) that such information, instruction, training, supervision and facilities are provided as are necessary to ensure the occupational health and safety of the workers;

(d) that workers and supervisors are familiar with occupational health or safety hazards at the workplace;

(e) that workers are made familiar with the proper use of all safety features or devices, equipment and clothing required for their protection; and

(f) that the employer's undertaking is conducted so that workers are not exposed to occupational health or safety hazards as a result of the undertaking.

(2) An employer shall

(a) consult and cooperate with the joint occupational health and safety committee or the representative, as applicable;

(b) cooperate with any person performing a duty or exercising a power conferred by this Act or the regulations;

(c) provide such additional training of committee members as may be prescribed by the regulations;

(d) comply with this Act and the regulations and ensure that workers at the workplace comply with this Act and the regulations; and

(e) where an occupational health and safety policy or occupational health and safety program is required under this Act, establish the policy or program.

(3) An employer shall establish and implement as a policy, in accordance with the regulations, measures to prevent and investigate occurrences of harassment in the workplace.

[S.P.E.I. 2018, c. 45, s. 3]