Industrial heat & cooling glossary.

The written program OSHA's proposed federal heat rule requires from covered employers. Documents hazard evaluation, water and shade provisions, work-rest schedules, acclimatization protocols, training, and emergency response. PPE — including active cooling vests — can be documented under the plan's hazard-control measures.

See the OSHA heat standard guide →

The Cal/OSHA Title 8 §3396 requirement for indoor workplaces in California reaching 82°F. Required elements: procedures for measuring temperature and heat index, water and cool-down provisions, acclimatization, emergency response, and training. Warehouses, manufacturing, restaurants, and most indoor employers are covered.

See the Cal/OSHA guide →

The 7–14 day physiological adaptation period during which a worker's body adapts to working in heat. Almost half of heat-related workplace deaths occur on a worker's first day; over 70% in the first week. OSHA's proposed rule requires written acclimatization protocols. Active cooling supports acclimatization by reducing core temperature buildup during the adaptation period.

A condition caused by muscle breakdown and muscle death. Industrial workers exposed to sustained heat and physical exertion are at elevated risk. Breakdown products from the damaged muscle can injure the kidneys. Construction workers in particular face rhabdo risk during summer heat with heavy physical labor.

Active cooling using thermoelectric (Peltier) modules powered by battery. No moving parts, no ice, no water. Performance is independent of humidity. Runtime depends on battery capacity; ClemaCore runs 8–12 hours with one battery swap and delivers a >25°F felt temperature drop.

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A cooling technology using packs that melt at a fixed temperature (typically 58–65°F) and hold that temperature until fully melted. Runtime per pack: 2–3 hours. Packs require re-freezing between uses (1–4 hours). PCM vests work in humidity but can't cover a full industrial shift without ice support.

A cooling vest that works by soaking in water; cooling is produced as the water evaporates from the fabric. Lightweight and cheap. Works well in dry climates; fails in high humidity (Gulf Coast refineries, summer warehouses) because the water cannot evaporate efficiently.

Any wearable device that creates a cooler microenvironment between the body and outer protective gear. Categories include phase change (PCM), evaporative, liquid cooling garments (LCG), fan-driven, and solid-state thermoelectric. The U.S. military uses "microclimate cooling" as the umbrella term for soldier cooling research.

A composite temperature measurement that accounts for ambient temperature, humidity, wind speed, and solar radiation. More accurate than dry-bulb thermometers for assessing real heat stress on workers. OSHA's proposed heat rule references WBGT-based action levels for high-heat triggers.

OSHA published its Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings NPRM on August 30, 2024. As of 2026, the proposed permanent federal heat rule has stalled, but OSHA continues to enforce heat hazards under the General Duty Clause and the heat National Emphasis Program (NEP) remains active. State-level rules in California, Washington, Maryland, Nevada, Colorado, Oregon, and Minnesota apply regardless.