Woot offers Carhartt Gear B0000373 Cargo Series Insulated 4 Can Lunch Cooler - One Size Fits All - Black for $11.36 (reg. $42.94) free shipping with Prime. 

Product Description:
500-Denier Cordura® ripstop nylon with Rain Defender® durable water repellent - Top haul handle - Insulated main compartment keeps contents cold - Interior mesh pocket to store ice pack - Side loop to hang additional gear - Hook-N-Haul hooks to attach to any Cargo series pack and retract into pocket when not in use