Which set of factors is typical for heat stress risk in BE facilities?

• A. Use of protective clothing that prevents overheating
• B. High environmental temperature, radiant heat sources, physical activity, humidity, acclimatization, clothing
• C. Having air conditioning at full power reduces risk
• D. Carrying out tasks slowly in shade

Answer: (B)

Heat stress risk comes from the combination of environmental heat with the body's work heat production and its ability to lose heat. The best answer lists all the pieces that raise the heat load: a hot environment, radiant heat from sun or hot equipment, physical activity that generates metabolic heat, humidity that hinders sweat evaporation, and clothing that traps heat or reduces heat loss. Acclimatization matters too because workers who are gradually exposed to heat develop better tolerance and improved thermoregulation, which lowers the risk.

In practice, this means that heat stress is not just about one factor. High ambient temperature and radiant heat increase the external heat load; humidity makes it harder to dissipate heat through sweating; physical effort raises internal heat production; and clothing can add insulation or block evaporation. Acclimatization helps the body cope with those loads.

The other options describe mitigations or actions that reduce risk rather than the factors that contribute to risk: protective clothing that supposedly prevents overheating is not a typical risk factor and can actually increase heat burden; relying solely on full-power air conditioning is not a set of risk determinants and depends on system effectiveness and other conditions; working slowly in shade reduces exposure and thus risk, rather than constituting a risk factor.