Pete, as a fellow brother in blue (reserve), vol. firefighter, one of only 5 Intermediate EMT's in our local ambulance service and a company first responder (job that pays the bills) I want you to know I will think of all of my fellow brothers and sisters during this event.
All preparations aside, I will point out that my EDC when on duty is normally a dry towel (packtowl) change of clothes, normally uniform related, 4 packets of Lipton Cup-O-Soup and my thermal mug, which is carried in addition to all of my other "stuff." Sometimes a business owner will offer free coffee, as will shelters. After about 18 solid mind numbing hours in the cold, wind and wet you'll probably want to contact your family and of course find some dry warm spot and change clothes. Most importantly stay hydrated. Get full rest when allowed and avoid too much caffeine. Don't try to overdue it either, as injuries are normally the result. A two hour nap will make all of the difference in the world for any of us. In closing; take care and let's all be safe out there! Hope this helps.