What does frequency refer to?

• A. The total exposure time to heat.
• B. The number of people in a crew.
• C. The rate of perceived exertion.
• D. Refers to how many times a person repeats a given exertion within a given period.

Answer: (D)

Frequency means how often something occurs, specifically how many times a person repeats a given exertion within a set period. This is the idea behind scheduling work cycles and training progressions: you measure how many repetitions happen in a minute, an hour, etc. It’s not about how long the work lasts (that would be duration or total exposure time), not the number of people on the crew, and not how hard the work feels (that’s the rate of perceived exertion). For example, if you perform a task and repeat it 12 times in two minutes, the frequency is 6 repetitions per minute. In practice, frequency helps design safe workloads and appropriate rest intervals to prevent fatigue and heat stress.