An innovative ad man Temerlin transformed the Southwest into a leading agency center by bringing national and international accounts to the area, as well as being a tireless supporter of advertising education, pro-bono activities and ethical practices.

Temerlin's career began as associate editor of Sponsor Magazine , an advertising trade journal in New York. While there, he was commissioned to write a radio show for the series “Gold Medal Doctors,” thus educating him to the ways of show business. He began his 50-year advertising career in 1953 as a copywriter for Glenn Advertising (now Temerlin McClain) in Dallas. After Glenn Advertising merged with Bozell & Jacobs in 1974, Temerlin became president of the new entity, Glenn, Bozell & Jacobs. Throughout his career, he was also the new business director for the agency.

In 1979 Temerlin was named chairman of Bozell & Jacobs. Through a series of mergers and name changes, he continued as chairman of Bozell, Jacobs, Kenyon & Eckhardt (1986-1989); Bozell (1989-1992); and Temerlin McClain (1992-2001). Upon Temerlin's retirement in December 2001, he was named chairman emeritus of Temerlin McClain.

In his early years, Temerlin brought the first large national and international accounts to the area, including Philippine Airlines and Hyatt Hotels. He soon opened offices around the world to meet client needs in Europe, Asia, Canada and Mexico. This national attention began to help other agencies attract talent and major clients from outside Texas and the southwest. All began to help Dallas, and indeed, the whole southwest, become one of the premier agency centers in the country.

As the agency grew, Temerlin won national advertising accounts including Greyhound Corporation, Warner Lambert, Pfizer, Max Factor and Quaker Oats. Later, with his guidance , the agency acquired Dallas-area based accounts such as American Airlines, JC Penney Company, Exxon Mobil Corporation and Texas Instruments. During his tenure and under his leadership, Temerlin McClain grew to become not only the largest agency in the Dallas/Fort Worth Metroplex, but in the southwest U.S. His understanding of the complexity of the retail service-driven business began to define the agency.

His enormous influence and contributions to the advertising industry is evidenced by the fact that in 2001, Southern Methodist University honored Temerlin by renaming its Division of Advertising the Temerlin Advertising Institute for Education and Research. This is the first advertising school that has been named after an advertising executive. Temerlin's awards and honors are equally as extensive. He received the Institute of Human Relations Award from the American Jewish Committee's Dallas Chapter, the 2001 Servant Leader Award from the Volunteer Center of Dallas, the “Best Man in Advertising” Awards from ADWEEK and McCall's magazine, the Neiman Marcus Silver Cup for contributions to the arts, and the Linz Award, the southwest's oldest recognition for the highest level of civic service and accomplishments.