What is the best way to keep a bearded dragon warm while driving across country?

Driving from Texas to California. Need help.

It depends if you are making a lot of stops. You can buy a battery powered heater or just keep him close to the heater?

Put him in a styrofoam cooler and tape a 40 hour heat pack to the underside of the lid. That should be enough keep him comfortable. Make sure you pack some crumpled up newspaper in the cooler as a cushion and to absorb any waste.http://lllreptile.com/store/catalog/reptile-supplies/deli-containers-shipping-boxes-packing-material/-/disposable-40-hour-heat-pack/

You can put him in a container that has holes to breath in put some paper towels on the bottom of it then get those feet warmers you put in your shoes wrap put a sock on it and put it underneath the container check it every so often to make sure it don't get to warm and buy some extra warmers so it doesn't run out that's how i transported my bearded dragons from mass to arizona driving across the country. and they were happy with that. hope that helps you out