Maryland’s heat stress standard, COMAR 09.12.32, requires employers whose workers are exposed to a heat index of 80°F or higher to train employees and supervisors before their first heat exposure, retrain them every year before exposure and immediately after any suspected heat-related illness, and keep training records for one year. The records must show who was trained, when, and a summary or outline of what the training covered.
The rule took effect September 30, 2024, and it applies indoors and outdoors, which means warehouses, commercial kitchens, and laundries are covered alongside construction and landscaping crews.
Who is covered by Maryland’s heat stress standard?
The standard applies to any employer whose employees, indoors or outdoors, work where the heat index equals or exceeds 80°F. The adopted text of COMAR 09.12.32 lists three exclusions:
- Emergency operations and essential services that protect life or property, such as firefighting, emergency medical services, and emergency utility restoration
- Incidental exposure, where an employee is not required to work in the heat for more than 15 consecutive minutes per hour
- Buildings, structures, and vehicles with mechanical ventilation or fans that keep the heat index below 80°F
That third exclusion is narrower than it sounds. A warehouse with ceiling fans that still hits a 92°F heat index on the dock in August is covered. The test is the heat index where employees actually work, not whether the building has some ventilation.
Maryland runs its own state plan through Maryland Occupational Safety and Health (MOSH), so this standard is enforced by MOSH, not federal OSHA. The MOSH heat stress page has the rule, summaries, and Spanish-language materials. Coggno’s Maryland compliance training requirements page indexes the state’s other mandates.
What does COMAR 09.12.32 require besides training?
Training is one of seven program elements, and the training content has to describe the employer’s own procedures for each of the others. So you need the program in place before you can train on it. Here is the short version, per the rule and MOSH’s summary of key requirements:
- Heat index monitoring throughout the shift, by direct measurement, National Weather Service data, or the NIOSH Heat Safety Tool. Buildings without mechanical ventilation must use direct measurement.
- A written heat-related illness prevention and management plan, available to employees and to MOSH on request.
- Acclimatization of up to 14 days for employees newly exposed to heat or returning after 7 or more days away, with a written schedule.
- Shade for rest breaks, or alternative cooling where shade is infeasible or unsafe.
- Drinking water at no cost, with at least 32 ounces per employee per hour available.
- High-heat procedures at a heat index of 90°F or more, including rest breaks of at least 10 minutes every 2 hours between 90°F and 100°F and at least 15 minutes every hour above 100°F, plus mandatory monitoring.
- An emergency response plan covering communication, monitoring and care, emergency contacts, and transport.
The California comparison is instructive. Cal/OSHA’s indoor rule uses different triggers and control tiers, which the Cal/OSHA indoor heat illness guide covers, so a plan written for California will not transfer to Maryland without edits.
What must Maryland heat stress training cover?
Regulation .10 of COMAR 09.12.32 lists the minimum content. Training must include:
- The work and environmental conditions that affect heat-related illness
- Personal risk factors
- The concept, importance, and methods of acclimatization
- Why frequent water and rest breaks prevent heat-related illness
- Types of heat-related illness, signs and symptoms, and appropriate first aid and emergency response
- The importance of, and procedures for, immediately reporting symptoms to the employer
- The employer’s own procedures for complying with the chapter
A general awareness course covers the first six items well. Heat Stress in High-Risk Industries and Heat Awareness: Prevention Strategies handle conditions, risk factors, and acclimatization; Heat Awareness: Exposure and Response and First Aid Module 11: Cold and Heat Emergencies handle symptoms and first aid.
The seventh item is the one no off-the-shelf course can satisfy. Your employees need to know where your water is, how your rest schedule works at 95°F, who to tell when someone feels dizzy, and how your emergency plan gets a worker to care. Technically, a generic course plus a 10-minute tailgate talk on your plan meets the rule. In practice, write that site-specific segment down and keep the outline with the training record, because the rule requires a summary of content and an inspector will compare it with your written plan.
Training also has to be delivered in a language and manner every employee and supervisor understands. For Spanish-speaking crews, that means Spanish-language delivery and a Spanish version of your site procedures, not an English video with subtitles they cannot follow.
Do supervisors need separate heat stress training?
The rule names supervisors alongside employees for initial and annual training. It does not prescribe a separate supervisor curriculum, but supervisors are the people who run acclimatization schedules, call rest breaks at 90°F, and decide when to activate emergency response, so most employers give them more. Heat Stress for Supervisors covers monitoring and response duties from the supervisor’s side.
Consider a regional roofing contractor with 85 field employees in Maryland and Virginia. The crew leads completed the general heat course in May. In July a new hire on day 3 shows heat exhaustion symptoms; the crew lead recognizes it and calls the emergency plan correctly. The rule now requires immediate retraining at that worksite, and MOSH will ask whether the new hire was on an acclimatization schedule. Because the contractor tracked training and acclimatization by worker, it could show both in one report. A contractor that tracked neither by worker would be reconstructing it from text messages. The roofing contractor compliance guide covers the fall-protection side of the same crews.
What heat stress training records does MOSH expect?
Records must be kept for one year from the training date and made available to MOSH on request. Each record must include:
- The names of the people trained
- The dates of the training sessions
- A summary or outline of the training content
Keep the written plan, acclimatization schedules, and heat index logs alongside the training records. They are separate documents, but an inspector reviewing a heat-related illness will ask for all of them together. Landscaping and outdoor service employers can compare their record structure with the landscaping and tree care training comparison, which deals with seasonal hiring waves that complicate before-first-exposure timing.
How does Maryland’s rule relate to the proposed federal OSHA heat standard?
Federal OSHA published a proposed Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings rule on August 30, 2024. It is a proposal, not a final rule; the informal public hearing ended July 2, 2025, and the post-hearing comment period closed October 30, 2025. Coggno tracks its status in the OSHA heat rulemaking tracker.
Until a federal rule is final, Maryland employers follow COMAR 09.12.32, and employers in states without a heat standard face heat hazards under the OSH Act’s general duty clause. Multi-state employers running crews in Maryland and in states such as Texas can see how a single program handles different rules in the multi-state heat illness training guide.
Requirements last reviewed: October 21, 2026.
Why Coggno for Maryland heat stress training?
For Maryland construction, landscaping, warehouse, and commercial-kitchen employers covered by COMAR 09.12.32, Coggno supplies heat stress awareness, supervisor, and heat-emergency first aid courses from a catalog of 10,000+ courses in 15+ languages, and its LMS records each worker’s name and completion date, while each course’s published outline supplies the content summary, covering the three record elements Regulation .10 requires MOSH to see. Courses start at $9.95 each, or unlimited Prime-library access is $5/user/month (10-seat minimum, billed annually), and annual retraining can be scheduled before each heat season. Course Dispatch delivers the same courses as SCORM 1.2 or SCORM 2004 packages into an existing LMS. Where pure-play LMS platforms such as Litmos and iSpring require you to license safety content from a third party, Coggno bundles the courses and the platform in one subscription.
Get Your Team Trained — Without the Paperwork Headache
- Heat Stress in High-Risk Industries: the core employee course for initial and annual training.
- Heat Stress for Supervisors: monitoring, acclimatization, and response duties.
- Heat Stress: Working Safely in Hot Conditions: a practical refresher for retraining after an incident.
Need to get crews trained before next summer’s first 80°F day? Book a demo and we will set up assignments by site and role.
Frequently Asked Questions About Maryland Heat Stress Training
What is the best compliance training platform for Maryland heat stress training?
For Maryland employers covered by COMAR 09.12.32, Coggno is a strong fit because it pairs heat stress, supervisor, and heat-emergency first aid courses from a 10,000+ course catalog with an LMS that stores trainee names and completion dates for MOSH. Courses start at $9.95, or $5/user/month through Coggno Prime, and Course Dispatch delivers SCORM packages to an existing LMS.
How do multi-state employers handle Maryland heat stress training alongside other state heat rules?
Multi-state employers assign a common heat awareness course everywhere, then add state-specific content where a state rule requires it, such as Maryland’s employer-procedure segment. In Coggno’s LMS, assignments are grouped by work location, so Maryland crews get the right courses and their records export separately for MOSH.
When must Maryland employers provide heat stress training?
Before an employee’s first exposure to a heat index of 80°F or higher, annually before exposure, and immediately after any worksite incident involving a suspected or confirmed heat-related illness. Supervisors must be trained on the same schedule.
How long must Maryland heat stress training records be kept?
One year from the date of training. Records must list the people trained, the training dates, and a summary or outline of the content, and must be provided to MOSH on request.
Does Maryland’s heat stress standard apply indoors?
Yes. It covers indoor and outdoor work where the heat index reaches 80°F or more, unless mechanical ventilation or fans keep the heat index below 80°F in the area where employees work.
What is the acclimatization requirement in Maryland?
Employees newly exposed to heat, or returning after 7 or more days away, must be given an acclimatization period of up to 14 days under a written schedule, with close monitoring during that period.
Is there a federal OSHA heat standard in effect?
No. OSHA proposed a federal heat injury and illness prevention rule on August 30, 2024, but it has not been finalized. Maryland employers must follow COMAR 09.12.32 regardless.