But heat itself — high temperatures, sometimes in triple digits, that afflict inland California each summer — is a political issue with life-and-death consequences. As the issue of workplace heat simmers in California and other states, some federal agencies are pondering adopting heat-related protections for their employees. And a new study by the Massachusetts-based Workers Compensation Research Institute concluded that California’s pioneering regulations have had a dramatic effect on heat-related injuries and illnesses. Still, agricultural and business groups have opposed both heat-related compensation bills. They say the workers’ compensation system isn’t equipped to make determinations about employers’ compliance with Cal/OSHA rules.