The keyword is dissipation.
What you want is a large amount of liquid on the right temperature. The larger the amount, the better (a large amount of liquid heats up less quickly because there's more to heat up. If it heats up too much, it isn't cooling much.). The relative heat of the cans will be dissipated by the liquid. It's important the cans are completely submerged.
Water from the tap is a quick fix, but if you have anything colder around that works as well. Filling the liquid with ice will keep the temperature of the water lower and is usually a good idea as well, if any is available.
If you happen to have a large (preferably filled) container in the freezer, you can throw this in the water as well. It will have the same effect as adding ice (the larger the container, the better). Keep in mind the container probably was there for a reason. However, one need can overrule another.