Heat, Cold and Weather Program

This program is the written, auditable system for the weather and the body’s response to it: heat strain in structural gear in July, hypothermia at a four-hour winter car fire, frostbite on a hose crew, a lightning strike on an aerial, a limb through a windshield in a wind event, and the carbon monoxide that collects around a generator in a rehab tent. When it is working, every officer knows the day’s heat or cold action level before the first call and what it changes; every extended incident and every training evolution has a rehab function with a thermometer, water, shade or warmth, and someone watching for the early signs; members are acclimatized before they are worked hard; recruits are never run to collapse; the aerial comes down and crews leave roofs and ladders when lightning is inside the rule; the aerial’s wind limit is posted in the cab and obeyed; carbon monoxide is metered where engines run; and every heat or cold illness is treated as an injury, reported and reviewed. The program is owned by a line officer through the Wildland and Interface team (which carries this program) with the Health, Wellness and Rehab team as the clinical partner, verified by the health and safety officer, and consulted on by the JOHSC.

This module is switched on for every department. It answers Program Profile Worksheet Part C question 22 (01 Program Profile Worksheet): members do any outdoor work. It does not replace Firefighter Rehabilitation Program, which owns the rehab function at incidents and training; this program sets the environmental action levels that trigger and shape rehab, and it owns the weather rules (lightning, wind, severe weather) and the carbon monoxide rule at scenes and in stations.

• Acclimatization. The body’s gradual adaptation to working in heat over one to two weeks of progressively longer exposure; it is lost within days of stopping.
• Action level. The environmental reading at which the department’s pre-planned controls (work-rest cycle, monitoring, rehab, stop) take effect.
• Clothing adjustment factor. The amount added to a measured WBGT to account for the heat load of the clothing worn; structural firefighting ensembles carry a large adjustment.
• Cold stress. The combined effect of air temperature, wind, wetness and work rate that drives body heat loss and can lead to hypothermia or frostbite.
• Heat exhaustion. Heat illness with heavy sweating, weakness, headache, nausea and a near-normal mental state; treated by stopping work, cooling and rehydration.
• Heat stroke. Life-threatening heat illness with a core temperature above about 40 °C and altered mental state; treated by immediate aggressive cooling before transport.
• Humidex. A Canadian index combining temperature and humidity into the temperature a person feels; used as a field proxy where no WBGT instrument is available.
• Rehabilitation (rehab). The incident function that gives members rest, cooling or warming, rehydration, food and medical monitoring, and releases them to work only on criteria.
• SpCO. The carbon monoxide saturation of the blood measured by a pulse CO-oximeter in rehab.
• Threshold limit value (TLV). The occupational exposure guideline published annually by ACGIH for heat and cold stress, adopted by reference in some provincial and territorial regulations (J22 Exposure Limits, Heat and Cold Stress).
• Wet bulb globe temperature (WBGT). The index that combines air temperature, humidity, radiant heat and air movement into one number used to screen heat stress.
• Wind chill. The temperature a person feels when wind is combined with air temperature; the basis for cold exposure limits.

Requirements that differ by province and territory (the regulation that adopts the TLVs, first aid coverage, compensation rules) are listed under Jurisdiction requirements below, each with its topic page. Full citations are in 02 Standards and Law Master Map.

R = responsible, A = accountable (one per row), C = consulted, I = informed. Generic roles are defined in 01 Roles and Responsibilities; team roles in 06 Program Improvement Teams.

Each element states the requirement, the minimum method, the evidence or record, and the stage.

Requirement. The department must have this program in writing, approved by the fire chief, consulted on with the JOHSC, reviewed within 12 months of adoption and at least every three years. It must rest on a hazard assessment by season and activity: structural firefighting in heat, wildland, extended winter incidents, water and ice, training evolutions, physical fitness testing, station and shop work, roadway work in wind and ice (CSA Z1010:18). (S1)

Minimum method. Complete toolkit T1 once, review it each spring and fall with the team’s appraisal, and after any heat or cold illness.

Evidence. Signed program; T1; JOHSC consultation record; review dates.

Requirement. The department must adopt written heat action levels keyed to WBGT against the threshold limit values and action limits for the metabolic rate of the task, with the clothing adjustment factor for structural ensembles and for wildland gear, and must state the humidex equivalents used when no WBGT instrument is on scene (CSA Z1010:18; ACGIH, n.d.). A WBGT instrument must be carried on the rehab unit or kit and at the training ground; readings are taken at the start of work and at least hourly while work continues in heat. Each level must name its controls: work-rest cycle, hydration schedule, rehab trigger tightening, active cooling, monitoring, and the stop level for non-emergency work and training. (S1)

Minimum method. Adopt the action level table in toolkit T2, filling the numeric thresholds from the ACGIH edition or other criteria the applicable regulation adopts (J22 Exposure Limits, Heat and Cold Stress); log readings on Form - Heat and Cold Stress Monitoring Log; dispatch broadcasts the day’s level with the morning weather brief.

Evidence. T2 with values; monitoring logs from the last three extended incidents and all live fire and physical training in heat; instrument calibration record.

Requirement. Every member must be trained to recognize heat exhaustion (heavy sweating, weakness, headache, nausea, cramps, near-normal mental state) and heat stroke (hot skin, confusion, collapse, seizure, a core temperature above about 40 °C), and to act: stop work, move to shade or cool air, remove bunker coat, hood and helmet, cool actively (forearm immersion, ice towels to neck, armpits and groin, misting with fans), rehydrate if conscious and able, and for suspected heat stroke cool first and transport second with EMS called at once (NFPA 1580, 2025); (CSA Z1010:18). Any member with altered mental state, a core temperature above 38 °C that does not fall in rehab, or a heart rate that does not recover to the release criterion is transported (NFPA 1580, 2025). Heat illness is an injury: it is reported and reviewed (CPSE, 2019, criterion 11A.2). (S1)

Minimum method. Rehab release criteria from Firefighter Rehabilitation Program (heart rate at or below 100 beats per minute (some protocols 110), blood pressure below 160/100, temperature below 38 °C, SpCO below 5 percent for non-smokers, no symptoms after at least 20 minutes’ rest (NFPA 1580, 2025)); cooling kit on every rehab unit; the heat illness pathway on the monitoring log.

Evidence. Rehab logs with vitals; injury reports for heat illness; training records.

Requirement. Recruits, new members and members returning after illness or a long absence must be acclimatized before full-intensity work in heat: progressive exposure over the first one to two weeks of training, with reduced work time on day one and daily increases (CSA Z1010:18; ACGIH, n.d.). Physical training and evolutions in heat must be planned against the day’s action level, with water, shade and a rehab function present, and a hard stop at the stop level. Heat illness is a recorded cause of firefighter training deaths in the United States data, and this element is the control (USFA, 2025). (S1)

Minimum method. The acclimatization schedule in toolkit T4 is built into the recruit timetable; the training safety officer holds the WBGT reading and the stop authority (Training Safety and Live Fire Program).

Evidence. Recruit timetable with the schedule; WBGT logs for every training day in heat; stop decisions recorded.

Requirement. Work-rest cycles must follow the action level: at the lowest level, rehab on the normal triggers; at higher levels, shorter work periods and longer rest, with the ratio set in T2 against the TLV work-rest allocation for the metabolic rate (ACGIH, n.d.). Hydration must be scheduled, not left to thirst: pre-hydration before the shift or evolution, about 250 mL every 15 to 20 minutes during work in heat, and about 250 mL per 20 minutes of work in rehab, water or electrolyte, no caffeine or energy drinks, food at incidents longer than three hours (NFPA 1580, 2025). Active cooling (forearm immersion, misting fans, shade, PPE off at the waist) must be available whenever the action level table calls for it (MLITSD, n.d., GN 6-12). (S1)

Minimum method. Hydration cache on every apparatus; cooling chairs or immersion basins, misting fan, shade on the rehab unit; the work-rest line on the monitoring log.

Evidence. Apparatus check sheets; rehab unit inventory; logs.

Requirement. The department must adopt written cold action levels keyed to wind chill, using the cold stress TLV work-warm-up schedule as the basis (ACGIH, n.d.) and the public wind chill guidance as the field proxy (Environment and Climate Change Canada, n.d.). Each level must name its controls: warm-up breaks on the schedule, a heated shelter (apparatus cab, rehab unit, bus or building), dry gloves and socks in the cache, rotation of crews on hose lines and exposed positions every 30 minutes or less at the higher levels, buddy checks for frostbite on faces and hands, and the stop level for non-emergency work and training. Members must be trained to recognize hypothermia stages (shivering and clumsiness; confusion and loss of shivering; unconsciousness) and frostbite (numb, pale, waxy skin), and to act: remove from cold, remove wet clothing, insulate, warm the trunk, no rubbing of frozen tissue, transport for moderate and severe cases (CSA Z1010:18). Wet turnout gear in cold is a hypothermia hazard; a dry change is kept on the rehab unit at extended winter incidents. (S1)

Minimum method. Cold action level table in T2; winter cache on the rehab unit per toolkit T6; the monitoring log carries the warm-up schedule.

Evidence. T2; winter cache inventory; logs from the last three extended winter incidents.

Requirement. Any member within 3 m of the edge of open water or ice must wear a Canadian-approved personal flotation device, and a thermal protective suit where the task puts them at risk of immersion; the 1-10-1 principle (one minute to control breathing, ten minutes of meaningful movement, one hour before unconsciousness from hypothermia) must be taught (MLITSD, n.d., GN 6-2 and GN 6-3; Lifesaving Society, n.d.). Full requirements are in Water, Ice and Swiftwater Rescue Program. (S1)

Minimum method. PFDs on every apparatus that may respond to water; the rule in the water SWPs; winter water calls flagged by dispatch for the cold action level.

Evidence. Apparatus inventory; training records; incident records.

Requirement. The department must adopt the 30/30 rule: when the time between a lightning flash and its thunder is 30 seconds or less, lightning is close enough to strike; outdoor non-emergency work and training stop, crews come off roofs, ladders, aerials and water, aerial devices are lowered and bedded, and work resumes 30 minutes after the last thunder (MLITSD, n.d., GN 6-8). At an emergency the incident commander weighs the life risk against the strike risk and records the decision; defensive positions, apparatus cabs and buildings are the shelters; nobody stands under a lone tree, holds a metal tool aloft or works a hose stream from an elevated position inside the rule. Lightning alerts from the weather service are routed to dispatch and broadcast (Environment and Climate Change Canada, n.d.). (S1)

Minimum method. The lightning rule in toolkit T3 and on the apparatus weather card; aerial lowering practised in the annual aerial drill; dispatch alert path tested each spring.

Evidence. T3; drill record; alert test record.

Requirement. Every aerial device’s wind limit (the manufacturer’s rating, commonly 56 km/h) must be posted in the cab and in the SWP, with the rule that the device is not raised or is lowered when gusts reach it (NFPA 1900, 2024). In wind events crews must treat trees, limbs, signs and wires as falling hazards, keep the 10 m downed-line clearance (SWP - Downed Power Lines and Utility Emergencies), and position apparatus out of the fall zone. In ice storms the program adds slip control (traction aids in the cache, sanding at scenes), hypothermia controls, and carbon monoxide awareness in homes running generators and in the department’s own operations. Severe weather alerts (wind, winter storm, freezing rain, heat, extreme cold) are routed to dispatch and read at shift change (Environment and Climate Change Canada, n.d.). A weather go or no-go rule for training is adopted (toolkit T3). (S1)

Minimum method. Cab placards; the weather card; the training go or no-go table; seasonal readiness checklist in toolkit T6.

Evidence. Placards; training cancellations recorded against the rule; T6 completed each season.

Requirement. Carbon monoxide must be metered wherever engines, pumps, generators, fans or heaters run near people: at every structure fire during overhaul (with SCBA worn until readings are below the department’s action levels, commonly 35 ppm carbon monoxide and 4.7 ppm hydrogen cyanide), in and around the rehab area and command post, in rehab tents and shelters with heaters, and in apparatus bays (Respiratory Protection Program; NFPA 1550, 2024; MLITSD, n.d., GN 6-51 and GN 6-36; NFPA 1585, 2025). Generators and heaters are placed downwind and away from rehab and command; shelters with fuel-burning heaters carry a carbon monoxide alarm. SpCO is screened in rehab when smoke exposure is possible (NFPA 1580, 2025). (S1)

Minimum method. Multi-gas meter with carbon monoxide and hydrogen cyanide bump tested at the start of every duty period on every first-due apparatus; carbon monoxide alarm in every rehab shelter; the placement rule on the rehab unit checklist; station exhaust under Facilities and Station Safety Program.

Evidence. Bump test records; readings on the monitoring log; rehab unit checklist.

Requirement. Dispatch must receive the weather service’s alerts and the department’s daily action level (heat or cold) and broadcast them at the start of each duty period and when they change; crews record the level on the monitoring log at any extended incident or training evolution (Environment and Climate Change Canada, n.d.). (S1)

Minimum method. Alert subscription at dispatch; the action level calculation assigned to the duty officer or dispatch using toolkit T2; the shift-change brief template includes a weather line.

Evidence. Dispatch log; shift-change records.

Requirement. Every heat or cold illness, every lightning or wind near miss, every carbon monoxide reading above the action level in a rehab area, and every rehab transport is reported as an injury or near miss and reviewed under Incident Investigation and Learning Program; trends are reviewed annually at the JOHSC (CPSE, 2019, criteria 11A.2 and 11A.7). Monitoring logs, calibration records and training records are kept in {{Records system}} per 05 Document Control and Records. (S1)

Minimum method. Monitoring log filed with the incident or training record; injury report per the reporting policy; annual trend line in the quarterly update.

Evidence. Reports; JOHSC minutes; the quarterly indicator worksheet.

Requirement. The team reviews indicators quarterly and appraises the program annually, with the rehab team and the medical adviser, against the outcome statement and the season’s events (06 Program Improvement Teams). (S2)

(a) Work-as-done. Before any heat, cold or weather rule is written or changed, the team runs a learning-team session with members who worked the last hot summer and cold winter: how crews really decide when to come out of a fire in July; what rehab looks like at a volunteer station’s two-hour grass fire with no rehab unit; where people warm up at a four-hour winter incident and what they do with wet gloves; who actually calls the aerial down in a storm; whether the carbon monoxide meter is on during overhaul or in the cab; what recruits are told about pushing through. The procedure describes that, with the margins added (Hollnagel, 2014; Conklin, 2012).

(b) Capacity and margins. The work goes right most days because members pace themselves, officers rotate the heavy tasks, someone always brings water, and the body has reserve. The reserve erodes with short staffing (nobody to rotate to), a culture that treats rehab as weakness, structural gear worn long past its task, a July fitness test on a day that should have been cancelled, and a winter scene with no warm place. The program protects the margin with action levels decided before the call, a rehab function that does not negotiate, acclimatization built into the recruit timetable, and stop levels that take the decision away from the person who least wants to make it.

(c) Just culture. A crew that skipped rehab, a recruit who hid symptoms, an officer who raised the aerial in wind, usually did so because the situation made it the sensible choice at the time. The response is to find what made it sensible and change the condition. The learning firewall applies: what members say in learning teams, rehab logs and after-action reviews is never used for discipline. Conduct concerns go to a separate process run by different people under Policy - Internal Responsibility and Accountability.

(d) Psychological safety. A member says it plainly: “I am done, I need rehab,” or “lightning is inside 30 seconds, aerial down.” The officer’s reply is fixed: acknowledge, act, ask what the member needs, no comment in front of the crew. The rehab officer’s decision to hold a member is final and is backed by the incident commander every time. Leaders show it is safe by going to rehab themselves and saying so, by cancelling training on the stop level and saying why, and by reporting back what the season’s numbers say and what changed (Edmondson, 1999)DOI.

(e) Learning link. A heat stroke, a hypothermia case, a lightning strike, a wind-driven aerial event or a carbon monoxide poisoning is at least a Tier 2 Post-Incident Analysis; a death is Tier 3 Independent Learning Review. A rehab transport, a heat exhaustion case, a near miss with a falling limb, or a carbon monoxide alarm in a shelter is a Tier 1 After-Action Review. The AAR questions: “Who was running on empty, and did anyone know?” “What was the action level, and did it change what we did?” “What made it hard to come out?” Method: Incident Investigation and Learning Program and, for the full tiers, Manual 02 - The Three Tiers and Event Triage.

• SWP - Wildland Deployment, LCES and Heat (shared with the Wildland and Interface Program; the heat and work-rest steps are this program’s)

Procedures this program depends on but does not own: SWP - Rehabilitation at Incidents and Training (Firefighter Rehabilitation); SWP - Aerial Device Operations and SWP - Downed Power Lines and Utility Emergencies; SWP - Ice Rescue and SWP - Swiftwater Rescue (Water, Ice and Swiftwater Rescue); SWP - Live Fire Training Evolutions (Training Safety and Live Fire); SWP - Diesel Exhaust and Station Zoning (Facilities).

Loop test. A member at a volunteer station reports on Monday that the rehab tent at Saturday’s barn fire had a propane heater inside and nobody had a carbon monoxide alarm. By Friday the item is in the register with the rehab officer as owner, the member has had a reply, and every rehab shelter and heater has been inventoried. Within the quarter a carbon monoxide alarm is in every shelter kit, the placement rule is on the rehab unit checklist and in the SWP, a change notice has gone to every station, and the item is closed with evidence in the quarterly update and reported to the JOHSC.

Audit category: Checklist - Wildland, Heat and Weather. The five questions an auditor asks first:

1. Show me the action level table with the adopted values and the clothing adjustment. Who decides today’s level, and how did the crews hear it?
2. Show me the last three extended incidents in heat and the last three in cold. Where are the monitoring logs, the readings, and the rehab entries?
3. Show me the last recruit class timetable. Where is the acclimatization schedule, and what were the WBGT readings on the hot days?
4. Pick an aerial. Show me the wind limit in the cab, and the last drill where it was lowered for lightning.
5. Show me the last heat illness report. Who reviewed it, what changed, and who was told?

For an accredited or candidate department the same evidence answers the criteria on risk management during emergency operations, rehabilitative medical evaluation, safety training and hazard reporting (CPSE, 2019, criteria 11A.8, 11B.1, 11A.5 and 11A.2).

Sudden cardiac death from overexertion and strain is the leading cause of on-duty firefighter death in the US data, on the fireground and in training (NFPA, 2026; USFA, 2025), and the US Fire Administration’s recommendations put heat-stress protocols beside cardiac screening and fitness (USFA, 2025). Exertional heat stroke has killed recruits during physical training and evolutions. Rehab is skipped at long incidents, cylinders are swapped without rest, and nobody takes a temperature. Carbon monoxide has poisoned members during overhaul without SCBA and in rehab tents heated by generators and propane. Hypothermia and frostbite come at long winter incidents and water and ice rescues; slips on ice injure more. Lightning has struck aerial operators and crews on roofs; wind has collapsed aerials and dropped limbs on crews (MLITSD, n.d., GN 3-3, 6-8, 6-12, 6-51). Enforcement findings in another province after the 2023 wildfire season centred on planning, training and supervision, not technique (Canadian Occupational Safety, 2025). This program answers each with a named element: action levels decided in advance, rehab that measures, acclimatization in the recruit timetable, the 30/30 rule, the posted wind limit, the carbon monoxide meter and the shelter alarm, and a report for every case.

Stage 1 (Foundation) minimum. This program adopted and signed; seasonal hazard assessment done; action level table with adopted values; a WBGT instrument on the rehab unit and at the training ground, humidex cards on every apparatus; rehab triggers and release criteria in force with the rehab program; acclimatization schedule in the recruit timetable; lightning 30/30 and aerial wind limits posted; multi-gas meter with carbon monoxide and hydrogen cyanide bump tested on every first-due apparatus; carbon monoxide alarm in every rehab shelter; hydration cache and cooling kit on every apparatus; winter cache on the rehab unit; dispatch alert path; heat and cold illness reported as injuries.

Cost (people). Team lead about one day a month; the duty officer or dispatcher’s five minutes a day for the action level; rehab function staffing at extended incidents (EMS partner or two trained members); the training safety officer’s time already counted in the training program.

Cost (money, order of magnitude; confirm locally). One WBGT instrument per rehab unit and training ground; a pulse CO-oximeter per rehab unit; carbon monoxide alarms for shelters; cooling chairs or basins and a misting fan per rehab unit; a heated shelter for winter; hydration and electrolyte consumables; humidex and wind chill cards; traction aids. The rehab unit itself, where the department lacks one, is a capital item on the rehab program’s worksheet; this program adds the instruments and consumables to the team’s five-year budget worksheet (06 Program Improvement Teams section 11).

This chapter relies on the following legal requirements, which differ by province and territory. Check your jurisdiction’s section on each topic page before adopting it.

Fill the numeric thresholds from the ACGIH edition or other criteria the applicable regulation adopts (J22 Exposure Limits, Heat and Cold Stress) and the public humidex and wind chill guidance (Environment and Climate Change Canada, n.d.). The structure is fixed; the numbers are the department’s.

Heat (WBGT with clothing adjustment; humidex as the field proxy)

Cold (wind chill; the TLV work-warm-up schedule as the basis)

Lightning. Flash-to-bang 30 seconds or less: aerial down and bedded; off roofs, ladders and water; non-emergency work and training stop; resume 30 minutes after the last thunder; shelter in cabs and buildings; emergency decision by the incident commander, recorded (MLITSD, n.d., GN 6-8). Wind. Aerial not raised or lowered at the device’s rated limit ({{Aerial Wind Limit}} km/h, from the manufacturer) (NFPA 1900, 2024); apparatus out of fall zones; limbs, signs and wires treated as falling hazards; 10 m from downed lines. Ice and freezing rain. Traction aids on; sand at scenes; slower approach; hypothermia controls at Yellow or above. Carbon monoxide. Meter on at overhaul, in rehab and at command; generators and heaters downwind and away; alarm in every shelter; SCBA until below the action level.

Water and electrolyte for the crew size; cups; cooler and ice; cooling chairs or forearm immersion basins; misting fan; shade shelter; blankets; heated shelter or access to a heated cab or building; dry gloves and socks; dry base-layer change; thermometer (oral or tympanic); WBGT instrument; humidex and wind chill cards; pulse CO-oximeter; carbon monoxide alarm for the shelter; food for incidents over three hours; the monitoring log and the rehab log; a sign-in board for accountability.

Completed by the team lead within 15 days of quarter end; goes to the program manager, the senior leadership team and the JOHSC.

The table in section 11 is the program’s accountability loop. Copy it into the team’s terms of reference (06 Program Improvement Teams section 12) with the department’s titles from 01 Roles and Responsibilities section 6. Defaults in one line each:

• Owner: program manager, Wildland and Interface team (line district chief), with the Health, Wellness and Rehab team lead as clinical partner.
• Doer: dispatch, company officers, incident commanders and safety officers, rehab function, training safety officers, members, station officers, HSO.
• Verifier: company officer each duty period; incident safety officer at every extended incident; training safety officer at every evolution in heat; HSO quarterly sample and two observed incidents; JOHSC seasonal inspection; internal audit annually; independent review every three years.
• Feedback: quarterly update inside 15 days; seasonal summaries; reply to the reporter inside five working days; change notices with every change.
• Closure: Corrective Action Register with a priority from P1 to P4 (a P1 the same shift, others inside five working days); escalation by priority as the register’s scale sets; evidence and verifier sign-off to close; monthly to the JOHSC, annually to the fire chief.

The Stage 1 minimum and the cost note are in section 14. For budgeting, transfer these lines to the team’s five-year worksheet: WBGT instruments; pulse CO-oximeters; carbon monoxide alarms; cooling and warming equipment; heated shelter; hydration and electrolyte consumables; cards and placards; traction aids; rehab function staffing for extended incidents; refresher training time.

American Conference of Governmental Industrial Hygienists [ACGIH]. (n.d.). Threshold limit values for chemical substances and physical agents and biological exposure indices (current edition).

Environment and Climate Change Canada. (n.d.). Public weather alerts for Canada; humidex and wind chill guidance [Web page]. https://weather.gc.ca

Lifesaving Society. (n.d.). Cold water immersion: The 1-10-1 principle. https://www.lifesaving.ca

Ontario Ministry of Labour, Immigration, Training and Skills Development [MLITSD]. (n.d.). Firefighter guidance notes (Section 21 Advisory Committee; individual notes revised to 2026). https://www.ontario.ca/document/firefighter-guidance-notes