Bone cement is sometimes used for vertebral body reconstruction following tumor removal. During such procedures, the polymerization of the methyl-metacrylate in the bone cement generates heat. Such temperature increase might cause damage to the nerve roots within the spinal canal. In the present study, pig cauda equina nerve roots were subjected to controlled temperature increases by means of a heat-generating probe. A temperature of 40 degrees C applied for 5 min did not cause any changes in nerve root function. However, 70 degrees C resulted in a complete block of nerve root function within 5 min. Histological nerve fiber damage was seen after exposure to 60 degrees C and 70 degrees C. The present study provides basic knowledge of heat-resistance properties of spinal nerve roots that might be directly applicable as guidelines for safety margins during surgical spine reconstruction procedures using bone cement.