I'm sure you would be put to work if you showed up but right now monetary donations will be much more needed to fund purchase of water and sheltering supplies for those without a home. I just returned home from Austin after volunteering for Red Cross. My knees started giving out so was sent home. 16 hours a day in the warehouse was very hard on my replacements for this old guy.
There was NO gasoline in Austin yesterday when I left so that will be an issue as transportation of shelter supplies will be job one. There is a large warehouse being set up in Austin to service the 10,000 person mega shelters from a fairly central location. The big shelters will be in Austin, SanAntonio and Dallas for now. Might be more needed if things go bad from Irma.