The TOS team often uses a thermal imaging camera to test and even debunk reported temperature fluctuations in the places we conduct paranormal investigations.
We use a very simple small camera that attaches to an iPad and provides a visualization of surface temperature, not ambient temperature. In other words it doesn’t measure the cold spots often felt by people at the site of a haunting.
But we can use the thermal imaging capabilities to scan a room and measure the changes in temperature on surfaces to help potentially identify other sources for these, such as ventilation or a drafty door or window.