Engineering controls modify the rate of heat exchange between workers and their environment. Air temperature and velocity are the main factors that affect heat lost or gained in the body. Heat loss occurs when the ambient air temperature is lower than skin temperature (approximately 95°F). Under these conditions, increasing air velocity with fans can increase the rate of heat loss. If the ambient air temperature is greater than 95°F, increasing ambient air velocity will cause the body to gain heat.
To reduce the effects of radiative heat, place a reflective screen between the radiant heat source and the worker(s). The type of reflective screen can vary in complexity, from insulated furnace jackets to reflective metal shields or reflective clothing like firefighters wear. Covering the body in normal clothing can also provide some protection from radiant heat sources.
Engineering Control Recommendations:
- Increase air velocity (if ambient air temp is 95°F or below).
- Use reflective or heat-absorbing shielding or barriers.
- Reduce steam leaks, wet floors, or humidity.