The objective of this research effort was to provide information about the design, implementation, and evaluation of a temperature increment chamber (TIC). A TIC can be considered as a sub set of a temperature gradient chamber, as there is only one temperature zone that is maintained above the ambient temperature. Advantages of this approach are the relative ease of maintaining this single temperature zone as compared to several zones and the physical maintenance of the system. The criteria used to evaluate the success of this design was the ability to maintain a constant temperature increment between the ambient and the chamber air temperatures as the ambient temperature changed during the day and that uniform temperature conditions existed between the upwind and downwind locations in the chamber, i.e., there were no hot or cool spots where plants were growing. Another evaluation criterion was to determine if plant responses, in this case winter wheat (Triticum aestivum L.) were different in the chamber compared to plants grown in the ambient atmosphere. The TIC was programmed to operate at 3 oC above ambient temperature. On sunny, partially cloudy, and cloudy days these differences were 2.82, 2.89, and 2.93 oC, respectively. Over these same days, the differences between the upwind and downwind temperatures, a measure of the uniformity, were -0.42, -0.32, and -0.63 oC, respectively. There were relatively large differences in the carbon isotope ratios of the grain, stem, and flag leaves of wheat grown in the TIC (20.4, 21.5, and 21.9 percent, respectively )and wheat grown under ambient conditions (19.0, 19.5, and 21.2 percent, respectively) .