Workers, especially new workers not accustomed to their environment, can be injured or killed by heat exposure. Older workers, obesity, pregnancy and other factors can combine to increase risk, and by occupation the most common industry for a reported heat death was in construction, followed by agriculture and mining. 

Heat stroke, heat exhaustion, syncope, kidney failure or injury and rhabdomyolysis are all possible when a worker is exposed to excessive heat and not given sufficient water, breaks and if working outside shade or in a hot interior.

Official government trackers show a problem but a small one, only 40 or so deaths per year, and several thousand injuries, but due to failure to report and self-reporting mechanisms, it is acknowledged the problem is much larger. When researchers used larger more complete data sets, including workers compensation claims across California, they discovered a likely 20,000 additional injuries occurred during high heat than would have occurred in lower temperatures. These 20,000 additional injuries are just for California. For all of the United States, injuries at this rate could exceed 150,000 per year.