OK, you are wading into an unknown facility, doing the arc flash study. Arc flash energies are unknown, yet you have to take off covers to find wires sizes, or sometimes expose breaker settings.

What's worse, it is a hospital. People get edgy when you shut off the ICU and the surgery suite. We generally do all the inspections live, with PPE and a live work permit from the facility.

NFPA 70E specifically talks about thermography, being less risk, requiring only HRC 2 PPE. We have been going with that level of PPE for arc flash inspections, since nobody is poking around inside live panelboards, they are simply opening a cover and observing conditions. Although we carry voltage rated gloves, they are seldom needed since we keep our hands where they belong - outside the panel!

Once we do the calcs, often IEEE 1584 says don't open up the can anymore. How do people handle inspections, vs. actually sticking tools or installing breakers in panelboards. Is the HRC 2 we've been using OK, or should we be using a different approach?

You should follow the task tables for removing covers, not IR scanning.

You are not "working on" the energized equipment and as such will not be crossing the Prohibited Approach Boundary and as such, depending on jurisdiction, VR rated clothing and tools may not be required.

After determining the calculations of the equipment & using the formula IEEE specifies in order to determine the incident energy versus going in with your thermal imager have you noticed an increase in the exposure energy specified in calorie/cm2? If so, then I would definitely recommend increasing the calorie ATPV rated clothing.