2l pop bottle with water in it can cool you pretty quick too. so much so that it hurts if you hold onto it for too long(possibly cooling blood too much and making yourself sick) using groundwater temps. its nice though to keep one near you around the feet to cool down quick.
smaller frozen water bottles are good for back pockets on coveralls. and a fan on the back and feet is fast way to cool down. (using sleeves over the airconditioner can cool you fast too.)
if you freeze the larger 4l milk jugs , just put it in the center of the room on the floor. could probably keep one in your car if you wanted to keep your floor area cooler without leaving your car on. (be sure do dump the water outside and throw the container away if it becomes too dirty.)
