A full Flex weighs upwards of 70lbs. Although the handles are designed and tested to support that weight we do not recommend lifting when full. The liquid inside can slosh around and throw off your balance causing a potential safety issue. 70lbs dropped from only a couple feet can really injure yourself, others and/or pets. We have a caster kit and leg extensions available (HERE) which hopefully will eliminate the need to lift your full Flex. If you have to lift your Flex into a chest freeze, for example, please use caution!