By no means should the can of milk be exposed to the direct rays of
a hot sun, either on the platform waiting for the delivery wagon, or
on the wagon. Give it shelter and shade of some kind, in both cases.
If a woolen blanket is wet in cold water and wrapped around the can,
the rapid evaporation from the blanket will keep down the temperature.
Everything that can be should be done to preserve milk in its normal
condition.