Physiological Monitoring for Heat Stress Management

What is Physiological Monitoring?

• A basic way to measure the level of an individual’s heat strain in response to heat stress conditions. This includes, but is not limited to, heart rate monitoring & body temperature measurement.
• It does not include parameters that may be considered medical monitoring (measuring blood pressure, oxygen saturation, urine testing, or cardiac rhythm).

By contrast: the WBGT measures environmental temperature conditions useful to establish work/rest schedules and exposure hazard evaluation (i.e., heat stress) but does NOT monitor worker specific physiological responses (heat strain response) to the thermal dose received.

Physiological Monitoring may be required when:

• WBGT monitoring is not sufficient or feasible.
• Work will occur that is likely outside of the established work/rest regimens
• Additional information on worker heat stress is needed
• Work will occur in semi- or impermeable clothing ensembles such as polyethylene coated Tyvek or vapor barrier coveralls
• Heavy to very heavy work is performed, regardless of clothing level

Hanford Tank Farms Thermal Stress Issues

• Extended outdoor work in anti-contamination clothing and respiratory protection
• Desert environment (high radiant loading/low humidity)
• Tropical work shift schedule options
• Record setting heat levels in 2014 and expected in 2015
• High exertion work requirements
• Past difficulty implementing engineering and admin. controls as part of planned work
• Aging workforce/high bump and roll influx of newer workers
• Worker job jeopardy concerns
• Bargaining unit labor contract issues
• Legacy issues of prior programs and practices
• Past reliance on ‘self-identification’ of heat stress symptoms