The war against germs has extended beyond the medical community and into offices, homes, and public places. Bacteria and viruses are fast-spreading and more complicated to contain the growth of our increasingly global economy and our warming planet. Certain environments where crowds gather and that have unacceptably high numbers of bacteria living on surfaces — like healthcare facilities, subway stations, and other public gathering places — require innovative ways to make them more hostile to bacteria, viruses, and other harmful microbes. In the fight against germ matter, antimicrobial lights are one relatively new approach that can be added to the arsenal. Using antibacterial, germicidal lighting continuously makes exposed areas inhospitable for bacteria and other harmful microbes to grow and become dangerous.