Hey, I think I can help. I was employed with the Department of Sustainablility and Enviornment in Australia for a fire season. It wasn't easy, but it can be done. I applied when I was here in Canada, but to be considered you have to be there. I had planned on being there for when they were hiring, so it worked out. They may call you on a Friday for an interview on Monday, so...
It was interview, medical, fitness then job offer. You have to have the appropriate visa to be considered also. I had a working holiday visa, which worked prefectly. If you plan on going back for a second season, you must be aware that you will only be granted if you work in Regional Australia (Immigration has a list of approved areas). You also have to be under 31 to do this as well.
If you have any questions, let me know. I would be glad to help and had the time of my life working with them. Amazing experience!