Extension cords

I bought an extension cord in Europe to use with my CPAP. I actually have not had too many occasions to use it because outlets near the bed have been pretty common. Nice to have just in case, though.

Buy an extension cord in France, it will be safer.

With or without an extension cord, if you are sure that your CPAP does not accept 230V (it is indicated in the user manual or on a label on the device), it is more prudent to buy a 220/110V voltage converter which supports the power that your device consumes.
Otherwise you risk destroying your CPAP

Check to learn the power requirements of your CPAP. If it is 110-120 volts only, you will need a Converter. Plug the converter into the power outlet, and then you can either plug your CPAP in the converter or plug it into a 110v extension cord plugged in the converter.

If the CPAP accepts 110-220v, you can use an Adapter which plugs into the power outlet and the CPAP either plugs into it or a 110-extension cord plugged into the adapter.

You can get converters, adapters, and extension cords for 110v and 220v at Amazon. To plug several iPads and iPhones into one outlet, I use the appropriate adapter into which I plug a simple 110v extension cord.

On a recent trip to Paris, I used an adapter with 2-USB ports and a single 110 outlet into which I plugged an iPhone 13 power supply. I could have also plugged in my 110-extension cord for other devices using 110v-220v power that were not located close to the adapter. I could not have plugged in devices using only 110v power. The USB ports on the adapter were engineered to work with 220v power.

Just pick one up when you arrive. Any Monoprix or hardware store will have extension cords. You'll have a useful cord for all future travels.
What you do need is a little plug adapter to put on the end of the CPAP cord. I'm sure you've looked at your machine and see it's dual voltage. Most are.

A US 110vac extension cord will work fine in France, as long as you have the necessary plug adaptors.

If you purchase an extension cord in France, be sure to never use it with 110vac. 220vac requires much smaller wire, and using it with a 110vac source can cause the wire to overheat.

Pop into a FNAC store for extension cords

Look at the charger of your CPAP machine. More than likely, much like a laptop, you'll see it will work fine with French voltage. You'll need an adapter for the plug though.

You can buy European extension cords on Amazon. I have an international power strip that's small enough and light enough to pack. Handy as we often have cameras, tablets and a laptop to charge too.

On a trip to Paris in 2015 we still needed an extension so I asked at the front desk for the nearest place to buy one. The manager overheard me and stepped out of his office with a cord for me. In French it's a "ralonge".