The fan will likely need a voltage converter, check on the fan itself, it will tell you what it can use in terms of volts and Hz. Anything with an electric motor - like a fan or hair dryer, may only work on a speficied voltage and hertz.

As others have posted, most chargers will accept any voltage between 110 and 240 and either 50 or 60 hz, and so for those you only need a plug adaptor, but do check the charger to see what it says about input voltage ( you may need a magnifying glass ) I have a few that are 120 volt only.