Reefer containers Use a refrigeration unit over the bulkhead end with the container. Although it isn't really a blast freezer, most reefer models are effective at protecting temperatures as little as -20F. Refrigerated shipping containers are insulated, and usually painted a light colour (like white or grey). 40ft High Cube https://raymondfgebx.boyblogguide.com/29943185/the-greatest-guide-to-20ft-used-shipping-container