How does thermal stress affect performance and safety in workers?

• A. It has no impact on safety.
• B. It decreases fatigue and improves concentration.
• C. It increases fatigue, reduces concentration, and raises the risk of heat-related illness and accidents.
• D. It improves decision-making.

Answer: (C)

Thermal stress impairs performance and safety by pushing the body to struggle with heat exchange, which leads to fatigue, mental slowing, and a higher likelihood of heat-related illness. When the body is overheated, you lose fluids and electrolytes, your heart works harder, and you may become dizzy or dehydrated. These physical strains spill over into the cognitive domain: attention wanes, reaction times lengthen, and decision-making becomes slower or less accurate. As fatigue and cognitive impairment accumulate, the chance of errors, mishaps, and accidents on the job rises. Heat-related illnesses like heat exhaustion or heat stroke become more likely as core temperature climbs, further threatening safety. All of this is captured by the statement that thermal stress increases fatigue, reduces concentration, and raises the risk of heat-related illness and accidents.

Other options miss the mark because they imply no impact or even improvements in performance or safety, which contradicts how heat exposure typically degrades physical and cognitive functioning and elevates safety risks.