I use mine for:

Checking circuit breakers to see if they are running too hot
Ditto cables

Behind suspended ceilings to pinpoint heat losses [which usually
indicate holes] when we have to 'gas-seal' a Server room

and to demonstrate to the 'boy' that just because the microwave had
pinged it did not mean that his pie was warmed through
completely....and later to show his mate what temperature his lips had
just experienced!!