If you're on a wood floor over a crawl space, you could have a plumber install a radiant heating system through your joists. It would be fairly expensive, but it can be done. Other than that, strategically placed throw rugs can always warm-up a hardwood floor as well as add an interesting design element to a room.

 

Good luck

To be honest, I'm not sure. I have only seen it done with hot water. You might ask a few electricians in your area if they've ever retrofit an electric radiant heating system. I've never heard of it, but I'm just a floor guy, so what do I know!?

In my area a hot water system with a gas-fired boiler is the most common. 

 

Good luck. 

In our Climate-Friendly Flooring section you'll find the pros and cons of the most common floor types in relation to humidity. Before purchasing new flooring for your home, it may be a good idea to first determine your region's humidity level. You may be surprised to know extremes in humidity can have a dramatic affect on certain floor types and result in damage that may be inconvenient and/or expensive to repair. Choose the floor best suited for your humidity level and help increase the longevity and performance of one of the largest surfaces in your home!