There are 3 things to consider regarding electric devices when travel to other countries...
1. Voltage: Countries either use 110V or 220V rating for public services. Most modern devices now can take both and convert it internally automatically. To make sure if your device does this, Look on your power part/charger of your device. Find the word "Input" and see if it said "100-240V" or similar. If there are 2 numbers like this, you don't need any voltage adaptor. If it say only 1 number, you may need voltage transformer - which typically heavy and cumbersome to travel with. Better not to take them along.
Note: Most appliance that work with heat (Hair Dryer, Hair Curler, Hair Straightener are most common) would be single-voltage. If you come from 110V country to 220V country, your appliance may burst into flame. If you come from 220V country to 110V country, it won't heat up enough.
2. Plug&Socket type: Different country, use different socket type. Most of the time you can search for your destination type on google. There are many countries that use "Similar but not exact" plug & socket. An Plug & Socket adapter will be required. It would be a good idea to save a picture of the type use in your destination from internet and go to your nearest store. Otherwise, buy a multiple adapter type that one unit have all the possibility. Also, it's a good idea to bring a "Power Strip" - or an extension cord with several socket from your original country. So that when you have only few wall socket, you can still use multiple appliance/device. and with this, you'll need only one adaptor. However, there's a caution that I'd say in No.3
3. Wattage: This refer to how much power all your device drain from the grid. Typically, device that give out heat would work on high Wattage. The procaution here is that you should not overload the power rating of your socket adaptor & power strip. Wattage of each device can be found either written as "65W", "30W", "10W" - these are typical range of mobile phone charger. Appliance work with heat, like hairdryer usually require "650W", "800W", "1000W". Total Wattage of all device to be plug in at the same time should not exceed the Wattage rating of the socket adaptor & power strip. Alternatively, Wattage require for the appliance may be presented as "5V 2A" - just multiply these numbers (V * A) and you'll get the wattage of your appliance in W (that example of 5V 2A give you 10W) If you exceed the rating of the powerstrip or socket adaptor, it may caught fire.
Hope this helps.
darkenergy.com
). For hair dryers, at lest in Europe, there are small compact ones for traveling readily availabe for less than €10 that work from 110 to 230V.
