Heat stress is a global issue that crosses socioeconomic status. Heat stress leads to reduced worker capacity on seasonal scales, and weekly to sub-daily timescales, incapacitation, morbidity, and mortality. This dissertation focuses on 2 distinct parts: quantification methods of heat stress, and heat stress applications.

Quantification methods of heat stress: Chapters 1--3 focus on historical analysis of heat stress. Chapter 1 is a detailed assessment of previous work in heat stress---methods, history, and future research out- look. Chapter 2 focuses on the implementation and quantification of a battery of heat stress metrics within the global circulation model framework. The ultimate outcome is a Fortran module, the HumanIndexMod [1], that may be run independently on individual datasets, or used with the Community Earth System Model 1, Community Land Model Version 5 (released February 2018 w/HumanIndexMod). Chapter 3 is an analysis of a battery of heat stress metrics with the focus on showing their differences in global circulation models, and thermodynamic predictability and scalability.

Heat stress applications: Chapters 4 and 5 focus on applications for physical impact modeling and economic outcomes. Chapter 4 quantifies labor impacts from heat stress due to the covariance or temperature, humidity, and radiation. My predictions of labor productivity losses from heat stress are amenable to Integrated Assessment Modeling. Chapter 5 is a preliminary economic impacts analysis--a 1st order sensitivity perturbation study for labor impacts--which will guide a flagship application for the Purdue University Big Idea Project, GLASS: Global to Local Analysis of Systems Sustainability. My labor productivity losses from heat stress will become a boundary condition for a series of sensitivity assessments intended to inform the policy making process to help achieve the United Nations Sustainability Development Goals.