An Infrared Thermographic Survey of Hunting Clothing Treated with Wraith
The imager used for the testing was a FLIR E40. Infrared imagery is often a grayscale or color image whose scales represent the differences in temperature of objects in the image. Generally, objects in the image that are lighter in color are warmer and darker objects are cooler. No object in the images included in this report is detected via visible light — only from infrared wavelengths in the 8,000–14,000 nanometer range.
Deer don’t see infrared — they sense it
It is important to understand that deer and other quadrupeds do not “see” infrared light. The cones and rods in their eyes do not see wavelengths in the infrared 8,000–14,000 range. Deer and other quadrupeds sense differences in heat through their thermoreceptors.
White-tailed deer (Odocoileus virginianus) possess thermoreceptors — specialized sensory receptors that detect changes in temperature, primarily located in their skin and certain mucous membranes. Thermoreception refers to their ability to detect temperature changes in their environment, which is critical for survival, behavior, and physiological regulation. While there’s limited research specifically on thermoreception mechanisms in white-tailed deer, we can infer from general mammalian physiology and available studies how they likely perceive and respond to temperature. Thermoreception likely works in concert with other senses (e.g., olfaction, vision) to inform decisions about foraging, predator avoidance, and habitat use. Thermoreception is likely one of the senses a deer uses that lead hunters to believe deer have a “6th sense.”
The FLIR E40 IR camera was used in our testing to collect data on the Wraith formulation’s ability to control a person’s thermal heat signature (radiant heat) compared to the ambient temperature of the environment the person is in. Therefore, the purpose of our testing is to understand the formulation’s ability to mask a hunter from a deer’s thermoreception sensors — not the formulation’s ability to “hide” a person from the infrared light spectrum and infrared optics.
Methodology
Testing was conducted in a controlled environment utilizing a 10′ × 12′ walk-in cooler, with decreasing ambient (AMB) temperatures. The test started in the low 70s and ran until the temperatures got to the low 50s. The total testing time was approximately 2 hours and 30 minutes. Note: the previous thermal regulating tests conducted were in a field environment with rising ambient temperatures that started in the low 70s and rose to the mid 80s.
An unbiased 3rd party oversaw the testing. The 3rd-party observer has been in the sporting goods industry for nearly 4 decades and is named on several patents. At the time of the testing the 3rd-party observer worked for one of the leading thermal optics companies in the sporting goods industry.
Cotton twill hunting coveralls were utilized for testing. Both the baseline (untreated suit) and the test suit (treated with the formula) were the same brand and model. Per the recommended method of application, the test outfit was turned inside out and the Wraith formulation was applied to the interior lining. The outfit was left inside out to dry for about 10 minutes, then turned right side out. The outfit was then put on by Brett, and Gary thoroughly applied the Wraith formulation to the outside of the test outfit Brett was now wearing.
Prior to testing, a wireless smart thermometer was taped to the chest area of the T-shirts of both Brett and Gary, between their two layers of clothing. This data was tracked to see if there was either an insulating effect or a cooling effect of the Wraith formulation — notated on the graphs as the Int Temperature. The external thermal temperature of both outfits was read by the FLIR camera — notated as the Ext Temperature. A Newentor wireless weather station monitored the AMB temperatures.
Results
As in the previous two field-environment tests, the controlled-environment test showed the Wraith formulation moderated the Ext Temperature of the treated outfit down to the AMB temperature of the environment. The Wraith formulation averaged 1 degree below (−1) AMB temperature. The untreated baseline person radiated thermal heat an average of 8.5 degrees over the AMB temperature.
Note: there was a 17.2-degree drop in AMB temps over the 2-hour-30-minute test. The baseline person’s Ext temp dropped 17.3 degrees (avg 8.5 degrees above AMB). The Wraith formulation person’s Ext temp dropped 24 degrees (avg −1 degree below AMB). These findings are consistent with two previous field-condition tests of the Wraith formulation.
We believe this ability to control and contain thermal heat relative to the environment’s AMB temperature is significant for the hunter — if, as some believe, deer through thermoreception are able to sense predators because of their thermal heat.
Running the thermometers under the treated outfit showed surprising data: the Wraith formulation, based on the data, has a significant cooling effect. The person treated with the Wraith formulation had an Int Temperature that averaged 13 degrees lower than the baseline person — the baseline stayed at 86 (except one reading at 84) for the entire test, while the treated person dropped from 84 to 68 degrees.
For those hunting in warm weather this is a significant finding, as Wraith will assist in keeping the hunter cool. However, when hunting in cold temperatures, Wraith should only be applied to the exterior layer of clothing.
Infrared pictures
For all the following pictures the baseline person is on the left and the Wraith-treated person is on the right — labeled on each frame.
Water-only cooling effect test
The thermal cooling effect of spraying a person down with water only lasted approximately 12 minutes and only affected the external temperature (radiant thermal heat). By 22 minutes the cooling effect was nearly completely gone. The internal temperature only changed by 2 degrees throughout the testing.
Note: these results are consistent with information provided from outside sources that applying water to a person only affects their thermal/IR signature for 10 to 30 minutes, depending on the temperature of the water applied and the external environment.