Evaluating the Impact of Simulated Climate Change on Physical Work Capacity of Agricultural Workers Exposed to Heat Stress

Climate change threatens agricultural workers’ health and productivity by reducing physical work capacity (PWC) due to heat stress. Understanding how climatic conditions affect physiology is critical. This study assessed maximal physical work capacity (VO₂max) in 12 healthy male agricultural workers (24–30 years) under controlled climatic conditions in a laboratory chamber using the Modified Naughton Protocol. Three environments were tested: neutral (20°C–25°C, 50%–60% RH), warm-humid (26°C–32°C, 70%–85% RH), and hot-dry (33°C–40°C, 30%–40% RH). VO₂max was estimated using the Modified Naughton Protocol during submaximal treadmill exercise. Heart rate, time to exhaustion, and energy expenditure were continuously monitored. Relative to neutral, VO₂max declined by 6.14% in warm-humid and 7.31% in hot-dry conditions (p<0.05). Time to exhaustion decreased by 27.23% and 33.8%, respectively, while energy expenditure increased significantly (p<0.05). These findings show marked impairment of physical performance with heat stress. Warm-humid and hot-dry climates significantly reduce agricultural workers’ physical work capacity, heightening physiological strain and increasing the risk of health and productivity loss. Immediate measures such as cooling strategies, structured work–rest cycles, and mechanization are needed. Tailored adaptation plans are essential to protect worker well-being and sustain agricultural output under climate change.