MOST EXPERIMENTAL STUDIES on wound healing have been directed toward either elucidation of the normal biochemical and histological sequence of repair following trauma or investigation of factors which may slow or accelerate normal wound healing. In neither type of work has more than scant attention been given to the effect of environmental conditions upon normal wound healing. The present paper reports an investigation of the effect of 2 environmental temperatures upon the rate of gain of tensile strength of sutured wounds. Methods and Materials Three experiments were performed in sequence using 480 male Sprague-Dawley rats of the same age and weight range. Determinate measurements were obtained on 348 animals. The same experimental design was used in all 3 experiments. Tensile strength measurements were made in all, while the parameters of food intake, body temperature (skin, wound, and rectal), and histological examination were each investigated in only one experiment. Also original