There's discussion about it on a firefighters' board here:
http://www.firehall.com/forum/showthread.php?t=1355
post #4 confirms that this is how they do things in Seattle.
I'm assuming Russell's 25% quote is based on a 24 hours on 72 hours off shift system.
Given that it involves being on call, its unlikely that a firefighter would be going to a fire without any sleep. Assuming the shift ran from something like 9am to 9am the next day and the firemean went to bed at 11pm - they'd have to be fighting fires constantly from 11pm to 9am to avoid getting any sleep at all.
Edited to add:
http://www.firehall.com/forum/showpost.php?p=10993&postcount=12
The 24 hour shift is used in many departments.
You are not "on call". You are at a station from 07:30 to 7:30.
Your duty day is as follows:
1) Turn over and sign in to replace the outgoing firefighter.
2) Apparatus and equipment inventory.
3) Station cleaning duties. Then on certain days you have to do brass, glass and grass. Then on a monthly rotation you test hose, strip and wax floors etc.
4) Station breakfast.
5) You are required to do one hour of physical fitness and two hours worth of drills every day.
6) You have battalion training, fire inspections and public relations most of the normal work day. In Seattle the stations are open to free blood pressure checks all day.
7) Then you have a station dinner. You will have a relaxed evening schedule and are allowed to go to bed at 10:00 PM (even though dozing in a recliner may happen sometimes).
8) Then all night you respond to calls if the bell hits. Most of your activity in Seattle is EMS and false alarms. Sometimes you will be awake the whole time but that is rare. The most runs I have ever had in a day was 21. I also had many shifts where we didn't "turn a wheel".
