Travel season is coming closer. In the planning for international trips, it’s important to consider electrical connections. Details that matter most are wall outlet configuration and voltage.

Canada is easy. Electrical power, plugs and outlets there are the same as in the U.S.

If you’re going to Mexico, some adapters may be needed. Mexican standard power is the same as here, 110 volts. But the Mexican plugs lack that third, round ground prong that you see on most American power cables. Consequently, there’s no hole for it in the wall outlet. Devices with low current draw, such as laptop computers and phone chargers, come with just the two flat prongs.

But in some cases they are polarized, requiring a larger left slot in the outlet. In both these cases, you need an adapter to plug your equipment into the wall.

It gets more complex when you travel to Europe or Asia. German appliance plugs are just about as big as their name: Schutzkontaktstecker. You couldn’t, and wouldn’t, fit an American plug into a German outlet. Don’t try to just use a plastic adapter, because voltage in most European countries is 220V, which can quickly fry equipment designed for 110V.

An exception exists for some laptop and phone chargers. Check the small print on the label. If it says “100-240V 50-60Hz” then you can safely use an adapter in Europe and Japan.

Equipment designed exclusively for 110V requires a more expensive converter (aka voltage inverter) that throttles the power down to the proper voltage. Those items can be bulky and quite heavy, and airline travelers may want to check on that before purchasing.

If you travel with appliances that have a high power draw, like a hair dryer or toaster oven, check the “Amps” on the label. It indicates, simply put, the “strength” of the current demanded by the appliance. If the converter doesn’t match up, it can overheat.

China is a recent example from my travels. The full-size plugs have three large prongs, unlike anything in the states. Power is 220V 50Hz, identical to Europe. But the wall outlets have an additional opening accepting two flat prongs of the “Mexican” style, so the iPhone and laptop plugged in without anything else.

Regarding hair dryers, it’s often easier and even cheaper to just buy one locally instead of toting a lot of equipment around.