Avonex must stay between 36 - 46 degrees Fahrenheit and must NOT be frozen. For this medication we recommend the Ice-N-Go. This set up will maintain an average temperature of 40 degrees Fahrenheit indefinitely while traveling. It is required that you add ice every 10 to 12 hours to achieve this result. The Polar Bear Cooler is leak proof, sweat proof, and makes traveling with medication safe and easy.