Interactive effects of different temperature regimes and anti-transpiration organic materials, Surround WP (kaolinite clay) and Raynox (sun-protectant), on two strawberry (Fragaria ×ananassa) cvs. Chandler and Sweet Charlie were investigated under controlled environmental conditions. Newly planted strawberries treated with Surround and Raynox were subjected to 20/15, 30/25, and 40/35 °C (day/night) temperature regimes and 16 day/8 night photoperiod in growth chambers for 42 d. Photosynthesis (A) and photochemical efficiency (Fv/Fm) were measured at 7-d intervals during the experiment. Plants treated with Raynox displayed greater resistance to high temperature (40/35 °C) compared to those treated with Surround. Net photosynthesis of both cultivars decreased significantly with time at 40/35 °C. There was no significant difference in photosynthetic rate between the two cultivars. Nevertheless, there was difference in plant biomass between the cultivars. Raynox provided more protection against high temperature, specifically in reducing stomatal conductance and limiting transpiration, than Surround.