Depends where you are ...
In the US, EMT-Basics are basically first-aid only. Splinting, O2, transport, bleeding control. Very few medication, glucose is OK, oxygen, sometimes epinephrine or albuterol for asthma.
EMT-Intermediates are fading away in most places. Usually first aid and can do some limited IV fluids.
EMT-Paramedics have about 40 drugs, can intubate, defibrillate, start IV's.

I've never heard of blood being carried or transfused in the field by EMTs. That being said, I know a doctor in NJ that, during his EMS fellowship, was doing on-scene blood transfusions. Again, this was a physician, not a paramedic or EMT.

And as Tjin alludes to, EMS doesn't ID people. Usually the PD, rarely the FD.