The "Timothy J. Barber Act" mandates the Secretary of Labor to conduct a comprehensive study on the effectiveness of Occupational Safety and Health Administration (OSHA) spending. This study specifically targets funds allocated for technical assistance and compliance assistance related to heat-related illness, assessing their impact at both national and regional levels. The primary goal is to determine how such spending can be made more effective in preventing heat-related illnesses among workers. Within 180 days of enactment, the Secretary must submit a detailed report to Congress, including findings and recommendations for legislative or other actions to improve the efficacy of these assistance programs.