Sherman traps are widely used in ecological studies to live-trap small mammals. However, confinement in traps can expose captures to potentially lethal temperatures, especially in warm climates and seasons. We assessed several strategies to mitigate excessive heating in Sherman traps, including trap perforations, reflective paint, insulation, and shade (with and without conduction between shading materials and the trap). We measured maximum internal trap temperatures and the duration of temperatures above 35 °C (a temperature likely to endanger small mammals in our region) and compared the effectiveness of the cooling strategies. All strategies except perforations kept maximum internal temperatures significantly cooler than control traps, and cover which provided shade without conduction had the lowest maximum temperature. All strategies except perforations and shade with conduction significantly shortened the duration over which trap temperatures were above 35 °C, and traps under shade without conduction provided the best protection. Our results provide information which can help trappers avoid accidental mortality and consequences associated with heat stress.