Abstract: A kit for cooling the blood in the carotid arteries includes a cervical immobilization collar and a cooling element. The cooling element may include a body-facing panel attached on a body-facing surface to a lining layer, an outward-facing panel, and cooling material disposed between the body-facing panel and the outward facing panel. The cooling material may comprise urea and Carbamakool™ in an amount sufficient to produce a temperature of 20° F. to 35° F. within a minute of activation when measured on the body-facing surface of the body-facing panel.