The period 23 June to 8 July 1976 to be one of the hottest experienced in this country within the last 250 years. During this period temperatures were being measured in a solid concrete bridge, a composite bridge, in the surfacing of a concrete box bridge, in elevated concrete slabs and on steel plates. The main text of the Report presents the variations in surface emperatures and/or effective temperatures of these structures during those sixteen days together with some of the maximum temperature differences measured through their different depths of construction. Temperatures measured on various types of surface, both on, and above, the ground are also mentioned.