As the timber bridge design has evolved, some engineers have been concerned about the integrity of the stress-laminated system in cold climates. The structural integrity of a stress-laminated bridge depends on the level of interlaminar compression (between the wood laminations). Temperature change can cause material shrinkage, which could lead to substantial performance problems based on material mechanics and the nature of the stress-laminated system. In this study, to determine the effects of thermal change on interlaminar compression, four stress-laminated timber deck sections were put through a warm--cold--warm cycle. Various interlaminar stress levels and three moisture content levels were tested. Results showed that interlaminar compression in stress-laminated decks of this size was not affected by extremely cold temperatures when the moisture content was less than 19% and when initial bar force was sufficient.