In developing countries, workers’ employed under high-heat furnace work environments are exposed to severe heat stress; an ignored occupational health hazard especially under the unorganized work-sectors. During hot summer season, lot of underprivileged workers are strained by harsh thermal work-conditions with subsequent health challenges, declining their productivity and attributes to financial burden. As compared to developed countries, absence of adequate regulatory guidelines and control policies increases the risk-severity under the rampant conditions. The aim of the present study is to gain insights on the prevalence of occupational heat-stress under high-heat furnace work environments with special reference to developing countries. Present review study recognizes the prevalent issues by summarizing the dominant heat-stress factors (environmental, individual, and physiological), suitable assessment strategies, and consequent negative impacts on health and productivity followed by encapsulation of related heat-stress assessment studies particularly from the developing countries. From the assessment studies, it’s evident that the predominant chronic heat-stress adversely impacts the workers’ health and accompanying performance loss. Apart from heat related morbidities, severe health impacts such as immunological suppression, renal/urologic anomalies, and sub-cellular DNA damage are also attributable to this occupational health hazard. The prevalent thermal work-conditions necessitates implementation of adequate preventive measures and control policies to ameliorate the workers’ productive capacity and social well-being. Remedial control interventions like proper ventilation design, installing reflective thermal protective shields, providing cooling spots, optimized cooling vest design, and sensor based intelligence may be considered as an effective control measures with emphasis on ameliorating the heat stress exposure under high-heat furnace work environments.