IR wouldn't be the first choice in a fire zone,
that is correct.. except these cameras that the fire fighters are being used for 2 purposed 1st being for life saving then fire location.. that are used in SMOKE zones..ie when all that is there to see is smoke....
Still true: but IR still has issues when the ambient temp is higher than the average body
The normal core body temperature of a healthy, resting adult human being is stated to be at 98.6 degrees fahrenheit or 37.0 degrees celsius. Though the body temperature measured on an individual can vary, a healthy human body can maintain a fairly consistent body temperature that is around the mark of 37.0 degrees celsius.
IR is the range of choice, it's just not the only wave length out there to have any use.

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to the topic :
If the price is within budget, and the name is a known and 'trusted' brand, then buy it :
if the capability for seeing through clothes is available, set a feed up here