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Home My WebLink AboutPR 581 HS - Extreme Weather Conditions (Heat And Cold) -1- PR.581.HS PROCEDURE PR.581.HS TITLE: EXTREME WEATHER CONDITIONS (HEAT AND COLD) Date issued: June 1999 Last revised: June 2011 Authorization: Senior Staff: 07 May 1999 1.0 OBJECTIVE To provide guidelines for supervisors and workers when extreme weather conditions occur. 2.0 DEFINITIONS In this procedure, 2.1 Extreme Weather refers to a variety of inclement weather occurrences, including: extreme high or low temperatures, lightning, hail, heavy rain, flooding, tornado/hurricane warnings, blizzards, ice storms, and any weather that could create unsafe road conditions. This procedure will deal with temperature extremes. 2.2 Cold Stress refers to the effect on the body when it is exposed to low temperatures. This could be due to a number of variables, including: air temperature, wind speed, and wind chill. If a person is experiencing cold stress a series of health complications can develop, including: frost nip, frost bite, or hypothermia. 2.3 Heat Stress refers to an increase in the body’s core temperature. This could be due to a number of variables, including; air temperature, humidity, radiant heat and the Humidex. If a person is experiencing heat stress a series of health complications can develop, including; heat rash, heat cramps, heat exhaustion, or heat stroke. 2.4 Humidex refers to the perceived temperature based on a combined me asurement of air temperature and humidity. 2.5 Wind Chill refers to the perceived temperature on exposed skin based on a combined measurement of air temperature and wind speed. 2.6 Work/Rest Schedule refers to the ratio of hours worked in extreme temperatures to breaks taken while removed from extreme temperatures. 2.7 Supervisor refers to principals, vice-principals, managers and supervisors. -2- PR.581.HS 3.0 RESPONSIBILITY 3.1 Superintendents, school principals, managers and supervisors are responsible for the implementation of this procedure. 4.0 PROCEDURE 4.1 With the exception of a minimum indoor temperature of 18 oC, applicable in most indoor workplace settings in Ontario, there is no mandated temperature (low or high) that requires employers to remove employees from the workplace. According to the Occupational Health and Safety Act, it is the responsibility of employers and supervisors to take every precaution reasonable in the circumstances for the protection of a worker. 4.2 Supervisors will: a) familiarize themselves with this procedure and be a ware of the circumstances that could induce heat or cold stress; b) monitor local weather conditions and implement appropriate responses to extreme weather conditions for each season; and c) use their discretion to determine whether or not current or forecasted extreme weather conditions conflict with their responsibility for maintaining a safe workplace. In exercising this discretion, supervisors will consult with the appropriate Superintendent and will ensure that the health and safety of student and staff is maintained at all times. Supervisors are also encouraged to consult Environment Canada’s website regularly for Extreme Weather Warnings. 4.3 Supervisors will make themselves aware of the appropriate control measures/responses to extreme temperatures for each season. Some examples of control measures/responses that can be put in place to minimize potential effects of exposure are: a) In the event of heat stress: (i) encourage staff to drink plenty of fluids, preferably cool water; (ii) encourage staff to avoid strenuous physical activity; (iii) encourage staff to wear lightweight, and loose clothing; (iv) encourage staff to avoid direct exposure to the sun (if possible) and where direct sun exposure cannot be avoided, wear a hat and apply sunscreen; and (v) when indoors in a non-air conditioned building, encourage staff to use all appropriate strategies to keep buildings cool (e.g.: open windows first thing in the morning and close them mid -morning as it starts to get hot outside, keep the blinds/curtains closed, consider use high vel ocity fans, consider running the ventilation system all night with the fresh air dampers full open and start closing them down in the morning as the heat starts to increase outside). b) In the event of cold stress: (i) establish ‘warm areas’ for lunch and work/rest breaks; (ii) encourage the use of warm protective clothing for outdoor work that is appropriate for the task, the temperature, and the weather conditions; (iii) encourage staff to wear multiple layers; -3- PR.581.HS (iv) if working conditions are also wet, ensure that employees are wearing appropriate footwear; (v) follow the work/rest schedule for cold working conditions, (Appendix A). 4.4 Supervisors will provide information and instruction to employees on the symptoms of heat and cold stress and assist them in seeking first -aid or medical attention, as appropriate and required, if they suffer from such symptoms. 4.5 Supervisors will refer to Appendices A and B for guidance on appropriate work/rest schedules and when it may be appropriate to discontinue work due to extreme temperatures. 5.0 APPENDICES Appendix A- Work/Rest Schedule for Cold Temperature Working Conditions Appendix B- Humidex Based Heat Response Plan 6.0 REFERENCE DOCUMENTS Board Policy P.058.HS: Occupational Health and Safety Board Procedure PR.506.SCO: Emergency School Evacuations/School Closings Canadian Centre for Occupational Health and Safety: OSH Answers Humidex Rating and Work Cold Environments – Working in the Cold Environment Canada website Ministry of Labour Health and Safety Guidelines - Managing Heat Stress at Work (updated August 2021 -4- PR.581.HS Appendix A Work/Rest Schedule for Cold Temperature Working Conditions No Noticeable Wind Wind 8 km/h Wind 16 km/h Wind 24 km/h Wind 32 km/h ºC Max. work Period (minutes) # of Breaks (minutes) Max. work Period (minutes) # of Breaks (minutes) Max. work Period (minutes) # of Breaks (minutes) Max. work Period (minutes) # of Breaks (minutes) Max. work Period (minutes) # of Breaks (minutes) -26º to -28º Regular Break Schedule Regular Break Schedule 75 2 55 3 40 4 -29º to -31º Regular Break Schedule 75 2 55 3 40 4 30 5 -32º to -34º 75 2 55 3 40 4 30 5 Non-emergency work should cease -35º to -37º 55 3 40 4 30 5 Non-emergency work should cease -38º to -39º 40 4 30 5 Non-emergency work should cease -40º to -42º 30 5 Non-emergency work should cease -43º to -65º Non-emergency work should cease -5- PR.581.HS Appendix B GENERAL INFORMATION Hot weather is defined and measured based on a variety of factors, including; air temperature, humidity and the Humidex. Humidex gives the most comprehensive and accurate measurement of how people will feel outdoors. Below is a chart outlining how the average person feels based on the Humidex. Factor Definition Air Temperature Refers to the temperature of the air as measured in degrees Celsius. Humidity Refers to the amount of moisture in the air. It affects the body’s ability to cool itself, making the air feel hotter than on a dry day. The Humidex Refers to the perceived temperature based on a combined measurement of air temperature and humidity. Supervisors should consider the following response pl an based on Humidex: Humidex Based Heat Response Plan Humidex Response 25-29  Supply water to workers on an “as needed” basis. 30-37  Encourage workers to drink extra water; and  start monitoring hourly temperature and relative humidity. 38-39  Each hour of work should include 15 minutes relief time;  Continue to provide adequate cool water and encourage workers to consume at least 1 cup of water every 20 minutes; and  Workers with symptoms of heat stress should seek medical attention. 40-41  Each hour of work should include 20 minutes relief;  Continue to provide adequate cool water and encourage workers to consume at least 1 cup of water every 15 minutes; and  Workers with symptoms of heat stress should seek medical attention. 42-44  Each hour of work should include 30 minutes of relief;  Continue to provide adequate cool water and encourage workers to consume at least 1 cup of water every 10 minutes; and  Workers with symptoms of heat stress should seek medical attention. 45 +  Only medically supervised work can continue.