Does Hair Color Change 'Perceived Temperature'? Up to 13.05℃ Difference Found in Hair Surface Temperature
Henkel Consumer Brands conducted an experiment on hair surface temperature differences based on hair color in an outdoor environment of 36.4℃, discovering a maximum difference of 13.05℃ between black and blonde hair. This research proposes 'cool colors' as a countermeasure against intense summer heat.
📋 Article Processing Timeline
- 📰 Published: April 22, 2026 at 19:00
- 🔍 Collected: April 23, 2026 at 00:02 (5h 2m after Published)
- 🤖 AI Analyzed: April 23, 2026 at 01:32 (1h 29m after Collected)
Changes in Hair Surface Temperature in an Outdoor Environment of 36.4℃
In recent years, intense heat has become the norm and a social issue, requiring multifaceted heat countermeasures in our daily lives. On February 24, 2026, the Japan Meteorological Agency announced that the average temperature for this summer (June-August) is expected to be "higher" nationwide compared to the normal year (average of 30 years from 1991-2020). This summer is also expected to be hotter than usual, requiring sufficient preparation.
Henkel Consumer Brands (Shinagawa-ku, Tokyo; Representative: Laurent Martin), which operates the hair cosmetic brand "got2b" that incorporates salon techniques and knowledge into home care products, focused on the difference in heat absorption by color, given that many Japanese people have black hair, against the backdrop of the intensifying summer temperature rise. To explore the possibility of heat countermeasures through hair color, we conducted a comparative verification of temperature differences due to hair color. As a result, it became clear that there is a difference in hair surface temperature depending on the hair color.
This experiment was limited to "hair surface temperature" and does not guarantee a reduction in heatstroke risk, but it indicates the possibility that "hair color" may contribute to head heat stress.
In this release, we present the verification results and propose a new way to enjoy hair color, "Cool Color," which not only gives a cool impression visually by dyeing hair to a high tone but also contributes to heat countermeasures.
Experiment Result Summary and Discussion
As a result of comparing the surface temperatures of 6 types of wigs (black hair and 5 types of colored hair) in an outdoor environment of 36.4℃, it was found that the temperature environment of the head differs depending on the hair color. In particular, blonde hair showed a result of up to 13.05℃ lower compared to black hair 20 minutes after the start of measurement, indicating that brighter hair colors suppress temperature rise.
Figure 1: Changes in hair surface temperature in an outdoor environment of 36.4℃
(Discussion 1) Brighter hair colors suppress the rise in hair surface temperature
In an outdoor environment of 36.4℃, many hair colors showed lower temperatures compared to black hair. Especially brighter hair colors such as blonde and pink tended to suppress temperature rise, resulting in differences in hair surface temperature depending on the hair color.
(Discussion 2) Temperature difference tends to expand over time
The difference from black hair tended to be larger after 10 minutes and 20 minutes than after 3 minutes. In an environment exposed to sunlight for a long time, the difference in heat absorption and accumulation due to solar radiation appeared over time, and the temperature difference due to hair color became more pronounced the longer the hair was exposed to sunlight.
(Discussion 3) Maximum temperature difference of 13.05℃ confirmed between black hair and blonde hair
The largest difference confirmed in the experiment was -13.05℃ recorded for blonde hair 20 minutes after the start of measurement (refer to Figure 2). 20 minutes after measurement, black hair's temperature rose to 62.82℃, while bleached hair remained at 49.77℃. This suggests that in an environment exposed to sunlight for a long time, there is a possibility of a significant difference in perceived temperature due to hair color.
When exposed to sunlight for 20 minutes in the same environment, blonde hair was 13.05℃ cooler than black hair.
Figure 2: Temperature comparison of black hair and blonde hair in an outdoor environment of 36.4℃
[Experiment Outline]
・Implementation period: September 2025
・Outdoor temperature/humidity: 36.4℃ / 60％
・Measurement time: 13:00
・Experiment method: Six wigs (black hair wig, existing bleached wig, and 4 wigs dyed with our products) were placed outdoors at 36.4℃ and 60% humidity, and the average of 25 measurements of hair surface temperature after 3, 10, and 20 minutes was taken.
Expert Opinion
Weather Forecaster Takeshi Amada
“An interesting initiative focusing on the relationship between hair color and heat. One of the new ways to spend summer comfortably.” / Weather Forecaster Takeshi Amada
In recent summers with continuous heatwaves, devising ways to lower the perceived temperature even slightly has become important. Just as the feeling of heat changes depending on the color and material of clothing, hair color is also affected by direct sunlight.
This verification is an interesting initiative that focuses on the relationship between “hair color and heat,” which has not received much attention until now. The result that a maximum temperature difference of 13.05℃ was confirmed between black hair and blonde hair is reasonable considering the characteristics of black, which easily absorbs light, and bright colors, which easily reflect it.
This could be a meaningful hint for anyone to overcome the intense heat, not only for those who work outdoors for long hours or students who engage in outdoor sports and are easily affected by direct sunlight, but also for those who commute to work or school, or who have many opportunities to go out during the upcoming leisure season. In an era called the “boiling earth,” considering heat countermeasures from this perspective is one of the new ways to spend summer comfortably.
In recent years, intense heat has become the norm and a social issue, requiring multifaceted heat countermeasures in our daily lives. On February 24, 2026, the Japan Meteorological Agency announced that the average temperature for this summer (June-August) is expected to be "higher" nationwide compared to the normal year (average of 30 years from 1991-2020). This summer is also expected to be hotter than usual, requiring sufficient preparation.
Henkel Consumer Brands (Shinagawa-ku, Tokyo; Representative: Laurent Martin), which operates the hair cosmetic brand "got2b" that incorporates salon techniques and knowledge into home care products, focused on the difference in heat absorption by color, given that many Japanese people have black hair, against the backdrop of the intensifying summer temperature rise. To explore the possibility of heat countermeasures through hair color, we conducted a comparative verification of temperature differences due to hair color. As a result, it became clear that there is a difference in hair surface temperature depending on the hair color.
This experiment was limited to "hair surface temperature" and does not guarantee a reduction in heatstroke risk, but it indicates the possibility that "hair color" may contribute to head heat stress.
In this release, we present the verification results and propose a new way to enjoy hair color, "Cool Color," which not only gives a cool impression visually by dyeing hair to a high tone but also contributes to heat countermeasures.
Experiment Result Summary and Discussion
As a result of comparing the surface temperatures of 6 types of wigs (black hair and 5 types of colored hair) in an outdoor environment of 36.4℃, it was found that the temperature environment of the head differs depending on the hair color. In particular, blonde hair showed a result of up to 13.05℃ lower compared to black hair 20 minutes after the start of measurement, indicating that brighter hair colors suppress temperature rise.
Figure 1: Changes in hair surface temperature in an outdoor environment of 36.4℃
(Discussion 1) Brighter hair colors suppress the rise in hair surface temperature
In an outdoor environment of 36.4℃, many hair colors showed lower temperatures compared to black hair. Especially brighter hair colors such as blonde and pink tended to suppress temperature rise, resulting in differences in hair surface temperature depending on the hair color.
(Discussion 2) Temperature difference tends to expand over time
The difference from black hair tended to be larger after 10 minutes and 20 minutes than after 3 minutes. In an environment exposed to sunlight for a long time, the difference in heat absorption and accumulation due to solar radiation appeared over time, and the temperature difference due to hair color became more pronounced the longer the hair was exposed to sunlight.
(Discussion 3) Maximum temperature difference of 13.05℃ confirmed between black hair and blonde hair
The largest difference confirmed in the experiment was -13.05℃ recorded for blonde hair 20 minutes after the start of measurement (refer to Figure 2). 20 minutes after measurement, black hair's temperature rose to 62.82℃, while bleached hair remained at 49.77℃. This suggests that in an environment exposed to sunlight for a long time, there is a possibility of a significant difference in perceived temperature due to hair color.
When exposed to sunlight for 20 minutes in the same environment, blonde hair was 13.05℃ cooler than black hair.
Figure 2: Temperature comparison of black hair and blonde hair in an outdoor environment of 36.4℃
[Experiment Outline]
・Implementation period: September 2025
・Outdoor temperature/humidity: 36.4℃ / 60％
・Measurement time: 13:00
・Experiment method: Six wigs (black hair wig, existing bleached wig, and 4 wigs dyed with our products) were placed outdoors at 36.4℃ and 60% humidity, and the average of 25 measurements of hair surface temperature after 3, 10, and 20 minutes was taken.
Expert Opinion
Weather Forecaster Takeshi Amada
“An interesting initiative focusing on the relationship between hair color and heat. One of the new ways to spend summer comfortably.” / Weather Forecaster Takeshi Amada
In recent summers with continuous heatwaves, devising ways to lower the perceived temperature even slightly has become important. Just as the feeling of heat changes depending on the color and material of clothing, hair color is also affected by direct sunlight.
This verification is an interesting initiative that focuses on the relationship between “hair color and heat,” which has not received much attention until now. The result that a maximum temperature difference of 13.05℃ was confirmed between black hair and blonde hair is reasonable considering the characteristics of black, which easily absorbs light, and bright colors, which easily reflect it.
This could be a meaningful hint for anyone to overcome the intense heat, not only for those who work outdoors for long hours or students who engage in outdoor sports and are easily affected by direct sunlight, but also for those who commute to work or school, or who have many opportunities to go out during the upcoming leisure season. In an era called the “boiling earth,” considering heat countermeasures from this perspective is one of the new ways to spend summer comfortably.