Could someone in the EMS/fire/responder community chime in as a professional to address these concerns that might dissuade a chaser from entering a fresh tornado damage path:
Dan,
I am a 28 year career Fire Battalion Chief in Texas. The risk on every item listed below is very real. But, by design, chasers find themselves as the first on scene in these damage paths on pretty regular basis. I would never suggest it is a good idea for untrained folks to operate in this dangerous situation. But, even without training, a storm chaser who finds themselves in this situation should call 911 to report destroyed homes. It is the ground truth that is needed to send help to those who may need it. This simple act of calling 911 is considered "Rendering aid".
1.) Risk of serious lacerations/punctures from sharp objects (glass, nails, sheet metal, etc).
Lots of laceration risks.
2.) Risk of live electric lines, both transmission/distribution and interior household wiring.
To stay alive, always treat them like they are live. Even worse is flashback when the power grid is down. A Lightning strike anywhere along the line can re-energize the grid.
3.) Risks from leaking gas lines and/or chemical substances.
Especially along railroads
4.) Risk of liability for improper treatment of victims (making a tourniquet too tight, worsening a broken bone injury, etc).
You can perform live saving functions, to your level of training, under the good Samaritan law. If your trained in first aid, you can perform first aid. If you are not trained on anything then sometimes rolling someone over may just open their airway.
5.) Being in the way of first responders (vehicle or in person).
You are not in their way if the responders are not there yet. Rule # 1, don't become part of the problem. When the responders get there, relay what you know and ask if they need help. I have allowed citizens to help on some pretty big incidents. If I don't need help, I thank them and send them on their way.
6.) Some basic equipment/tools/clothing items to keep in a vehicle for these purposes.
Get trained in First aid and CPR. Bring what you need to take care of yourself and a first aid kit. Those who carry medical gear routinely are not always covered by the Good Sam law. Those who claim they are a first responder and are not can be subject to some legal issues.
Let's get some basic training information out there dealing with each one of those items (procedures/best practices/etc.) If we get enough replies, I'll separate them into their own post and sticky it.