Most manufacturers can tell you exactly what they spend on energy each month. Far fewer can quantify the cost of excessive heat in lost production, employee turnover, declining productivity, and operational disruption.
That gap is becoming increasingly important for manufacturers whose production processes generate significant heat. Plastics extrusion, food processing, foundries, chemical production, glass manufacturing, and other heavy industrial operations often combine high internal heat loads with aging building systems, limited natural ventilation, and long production schedules. In many cases, the facility was designed around the needs of the production process, not the long-term performance of the workforce or the evolving weather in which they operate.
For decades, workplace heat was viewed as an unavoidable condition of manufacturing. Employee complaints often resulted in additional fans, portable cooling equipment, or modified break schedules, but the conversation rarely extended beyond maintenance or facilities management.
Manufacturing leaders have spent years improving production lines, automation, supply chains, and equipment reliability. Increasingly, they recognize that the facility’s performance plays an important role in operational success. Thermal performance has become another factor influencing productivity, workforce stability, energy consumption, operational resilience, and long-term capital planning.
What is Thermal Performance?
Thermal performance is the ability of a manufacturing facility to manage heat, humidity, airflow, and building conditions in ways that support safe, productive, and efficient operations. It extends beyond HVAC systems to include how the facility, manufacturing processes, workforce, and supporting infrastructure perform together.
For manufacturers, improving thermal performance is more than employee comfort. It is about creating an environment that enables consistent production, supports workforce retention, protects equipment performance, and reduces long-term operating costs.
Regulatory Expectations Continue to Expand
Although a comprehensive federal OSHA heat standard has not yet been finalized, workplace heat remains a major enforcement priority. OSHA’s most recent National Emphasis Program addresses Outdoor and Indoor Heat Related Hazards and focuses on industries where employees face elevated heat exposure, including manufacturing, warehousing, and distribution. Employers may also be cited under the General Duty Clause when workplace heat presents a recognized hazard.
California implemented an Indoor Heat Illness Prevention Standard in 2024. Oregon, Washington, Maryland, Minnesota, and Nevada have established their own workplace heat requirements, each with different temperature thresholds and employer responsibilities. Illinois is also considering the Workplace Extreme Temperature Safety Act, legislation that would require employers to develop formal heat illness prevention programs, provide recovery areas, establish emergency procedures, and train employees when workplace temperatures exceed defined limits.
Whether every proposal becomes law is only part of the story. The broader trend is clear. Workplace heat is receiving increased attention from regulators across the country. At the same time, the engineering assumptions used to design manufacturing facilities are evolving as well.
Engineering Standards are Changing as Well
ASHRAE has updated the climate data used to design HVAC systems to reflect more recent weather conditions. Those updates recognize that many regions are experiencing warmer temperatures and higher humidity than previous design standards assumed. As a result, systems designed years ago may no longer deliver the expected level of performance under today’s operating conditions.
In the United States, we have higher dry temperatures for cooling design across the West, while the South and East display higher humidity levels.
Humidity is becoming particularly important. As wet bulb temperatures, the combination of air temperature and humidity into a measure of heat stress, continue to rise, cooling systems must remove more moisture from the air rather than simply lower the temperature. That additional latent cooling load influences equipment sizing, electrical infrastructure, operating costs, and long-term system performance. For facilities with significant process heat, understanding humidity can be just as important as understanding the temperature shown in the thermostat on the wall.
What is the Business Impact of Workplace Heat?
The greatest cost of workplace heat does not appear on a utility bill. It shows up through slower production, higher labor turnover, increased fatigue, inconsistent quality, and operational interruptions.
For many manufacturers, heat has traditionally been viewed as a facility issue or an employee comfort concern. In reality, it creates operational friction throughout the organization. As temperatures and humidity rise, physically demanding work becomes more difficult to sustain, increasing fatigue, reducing concentration, and placing additional strain on the workforce. Over time, those conditions can contribute to absenteeism, higher turnover, and greater difficulty attracting and retaining skilled employees.
The operational effects also often extend beyond labor. In facilities with continuous production, heat can disrupt the consistent quality that manufacturers work so hard to achieve. Additional recovery breaks, slower production rates, and temporary interruptions affect equipment utilization, throughput, and production schedules. Restart procedures consume valuable time, quality inspections may increase, and small inefficiencies repeated throughout a shift can accumulate into millions of dollars in lost productivity over the course of a year.
Most organizations already measure production output, equipment utilization, labor efficiency, and energy consumption with remarkable precision. What is often missing is an understanding of how thermal conditions influence each of those metrics. When heat is evaluated alongside operational performance rather than separately from it, the conversation shifts from managing employee comfort to improving business performance.
Is Air Conditioning the Best Solution?
Manufacturing facilities are fundamentally different from office buildings. Industrial processes generate radiant heat. Large overhead doors introduce outside air. Building envelopes may no longer perform as intended. Existing electrical infrastructure may already be operating near capacity, and production schedules often leave little opportunity for extended shutdowns. Simply installing larger HVAC equipment rarely solves every problem.
Many facilities benefit from a broader evaluation that considers equipment shielding, elimination of uncontrolled air infiltration, localized cooling, process exhaust, humidity control, and equipment efficiency alongside traditional mechanical upgrades. The objective is to improve thermal performance across the entire operation while balancing operating costs, energy use, workforce comfort, production continuity, and capital improvement investments.
How Should Operators Prioritize Facility Investments?
The most effective response to workplace heat begins with understanding where it is creating operational risk, not simply where temperatures are highest. That understanding leads to better operational decisions and a more informed capital strategy.
No two manufacturing facilities are exactly alike. Process heat, climate, building age, production schedules, workforce demands, and existing infrastructure all influence how heat affects operations. While one facility may struggle with seasonal productivity declines or employee turnover, another may face aging mechanical systems, limited electrical capacity, or increasing regulatory pressure. The solution should be driven by the business challenge, not by a one-size-fits-all approach to cooling.
A Thermal Performance Assessment is a comprehensive evaluation that assesses multiple factors specific to the organization and its location(s) to identify where heat is creating business risk today and to prioritize investments that will deliver the greatest long-term operational value. For corporations with a portfolio of production or manufacturing facilities, this approach provides an even greater advantage. Instead of reacting to individual issues as they arise, executives and leaders can compare facilities using a consistent data-driven framework, prioritize capital investments where they will yield the greatest return on investment, and develop a long-term strategy that aligns facility performance with business objectives.
As regulatory expectations evolve, engineering standards continue to advance, and manufacturing facilities age, Thermal Performance is becoming another measure of operational excellence. Organizations that understand where thermal underperformance exists today will be better positioned to improve production consistency, strengthen workforce performance, and make more informed capital investment decisions for the future.
Have questions about workplace heat, facility performance, or capital planning? Email Luis to discuss how thermal performance can improve operational efficiency, workforce productivity, and long-term facility strategy.
Connect with Luis
Luis Lara is Vice President of Energy Strategy & Solutions for Stream’s Manufacturing, Food & Beverage, and Distribution team. He guides clients toward high-performance, energy-efficient facility solutions, combining deep expertise in energy modeling, decarbonization, and MEP systems with a data-driven approach to capital planning. He has helped organizations like ABB and Chick-fil-A align sustainability goals with measurable operational results.
