Difficulty: Easy
Correct Answer: all (a), (b) & (c).
Explanation:
Introduction / Context: Heat stress is a key occupational hazard in foundries, refineries, and process plants. It affects worker safety, productivity, and error rates. Understanding combined effects helps justify ventilation, cooling, and administrative controls.
Given Data / Assumptions:
Concept / Approach: The human thermoregulatory system responds to heat by increasing skin blood flow and sweating. This often causes fatigue, dehydration, and changes in respiration and heart rate. Cognitive and manual performance decline as thermal strain increases, reducing efficiency and elevating accident risk.
Step-by-Step Solution:
Map common symptoms: fatigue from sustained thermoregulation and dehydration.Physiological response: elevated breathing and heart rate to dissipate heat and supply oxygen.Performance effect: declines in alertness and precision → reduced efficiency.All listed outcomes occur; choose “all (a), (b) & (c).”Verification / Alternative check: Occupational guidelines (e.g., WBGT-based) tie work-rest cycles and hydration plans to mitigate these effects, confirming their prevalence.
Why Other Options Are Wrong:
Each single item (a), (b), or (c) is true; the comprehensive choice is the combination of all three.Common Pitfalls: Underestimating respiratory changes; workers often hyperventilate subtly in hot conditions, especially with physical exertion.
Final Answer: all (a), (b) & (c).
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