A thermal imager has become one of the most valuable diagnostic tools in my kit. With IR cameras now available in the $300-600 range (FLIR C5, FLIR ONE Pro that plugs into your phone), residential and small commercial electricians can use them on every service call. What a thermal imager shows you: hot connections under load, overloaded circuits, unbalanced loads, failing components in panels and switchgear, and loose terminations that haven’t tripped a breaker yet.
The technique: take your image under load, not at no-load. A loose connection that gets hot under 80% load may look fine at 10% load. Schedule thermal inspections during peak operating times if possible. Compare like to like - a phase conductor that’s 15 degrees C hotter than the other two phases on the same panel indicates an imbalanced load or a problem on that phase.
For the business case: including a thermal scan with every panel replacement and service upgrade is a premium upsell that costs you 10 minutes and provides real value. Some insurance companies now require annual thermal scans on commercial electrical systems - and some offer premium discounts for systems with clean thermal histories.