Possibility of 2026 Summer Being 'Like the Japanese Archipelago is Inside a Giant Steamer' (Meteorologist Masaaki Masuda) - Independent Survey Reveals About 90% of Outdoor Workers Experience Decreased Job Performance Due to 'High Temperature and Humidity'

Kao Corporation's medicated bath additive 'Bub' (hereinafter referred to as Bub) conducted a survey of 500 men and women nationwide engaged in occupations involving outdoor work regarding the impact of summer heat and humidity on job performance.

As a result, it was found that about 90% of people working outdoors in the summer experience a decrease in job performance due to 'high temperature and humidity,' and about 90% feel a 'sticky fatigue*'. Furthermore, it was revealed that about 40% of those who feel this sticky fatigue* do not take baths or take them infrequently in the summer for reasons such as 'I don't want to take a bath because it's hot.' This highlights the reality that despite feeling fatigued, they are missing opportunities to recover from fatigue through bathing.

'Bub Medicure,' formulated with high-concentration carbonation*1 and hot spring ingredients*2, is a quasi-drug that enhances the warm bath effect and is effective for fatigue recovery, stiff shoulders, and lower back pain. In particular, 'Cooling Cool' contains a high amount of menthol (cooling ingredient)*1. It is refreshing both during and after the bath, lowering the psychological hurdle to bathing in the summer.

Bub will continue to support fatigue recovery through bathing, especially in the hot summer, and cheer on everyone's daily lives.

*Sticky fatigue: The feeling of fatigue during the season when you get sweaty.

*1 Comparison target: Our Bub Cool Refreshing Mint Scent

*2 Sodium bicarbonate, sodium carbonate

Survey Result Summary

1. About 90% of people working outdoors in the summer feel a decrease in job performance due to 'high temperature and humidity.'

92.0% of respondents answered that their job performance (concentration, work efficiency, judgment, etc.) decreases even slightly on days with high temperature and humidity.

2. On days with high temperature and humidity, about 50% feel a negative impact on communication in the workplace.

54.0% of people feel that communication with others in the workplace is negatively affected on days when the temperature and humidity are high and they feel sticky, revealing that interpersonal relationships are also affected.

3. About 90% of people working outdoors in the summer feel 'sticky fatigue*.'

85.0% of people feel 'sticky fatigue*' (a state where the body and clothes are sticky with sweat, or a feeling of fatigue due to the heat).

4. Among those who feel sticky fatigue*, about 40% do not take a bath because 'it's hot' - missing opportunities for fatigue recovery.

It was revealed that about 40% (39.8%) of those who feel sticky fatigue* take a bath twice a week or less on weekdays in the summer. The number one reason for not taking a bath is 'I don't want to take a bath because it's hot' (52.1%). This highlights the reality that despite being aware of their fatigue, psychological hurdles prevent them from taking a bath to recover.

Survey Results

1. About 90% of people working outdoors in the summer feel a decrease in job performance due to 'high temperature and humidity.'

92.0% of respondents answered that their job performance decreases even slightly on days with high temperature and humidity. As specific impacts, 'cannot maintain concentration' (55.0%), 'work speed drops' (50.2%), and 'judgment/thinking ability dulls' (41.7%) occupied the top spots, and concerns about safety such as 'mistakes increase' (30.7%) and 'confirmation work becomes sloppy' (27.0%) were also highlighted. In addition, 40.6% of those who feel a decrease in performance have actually been pointed out by their bosses or colleagues, and in the free answers, many specific failure episodes were collected, such as 'My head was fuzzy from the morning and I was late for a client' and 'I couldn't see ahead because of sweat and dropped construction materials.'

2. On days with high temperature and humidity, about 50% feel a negative impact on communication in the workplace.

54.0% of respondents answered that communication in the workplace is negatively affected on days with high temperature and humidity. Specifically, 'I'm worried about sweat and odor and it's hard to get close to people' (53.0%) and 'Conversations become shorter/sloppier' (52.2%) were mentioned, showing that interpersonal relationships are also seriously affected.

3. About 90% of people working outdoors in the summer feel 'sticky fatigue*.'

85.0% of people feel 'sticky fatigue*' (a state where the body and clothes are sticky with sweat, or a feeling of fatigue due to the heat) caused by the summer heat. In addition, 85.2% of people feel that work is exhausting on days with high temperature and humidity, revealing the harshness of working in a hot and humid environment.

4. Among those who feel sticky fatigue*, about 40% do not take a bath because 'it's hot' - missing opportunities for fatigue recovery.

It was revealed that about 40% (39.8%) of those who feel sticky fatigue* take a bath twice a week or less on weekdays in the summer. The reasons for not taking a bath were 'I don't want to take a bath because it's hot' (52.1%) in first place, followed by 'Because it's a hassle' (35.9%) in second place, highlighting the reality that despite feeling fatigued, they are missing opportunities to recover from fatigue through bathing due to psychological hurdles.

Survey Overview

Target: Men and women engaged in occupations involving outdoor work

Age: 20 to 59 years old

Region: Nationwide

Sample size: 500 people

Survey method: Internet survey

Survey period: January 22 (Thu) to January 23 (Fri), 2026

[Expert Comment] Meteorologist Masaaki Masuda

Possibility of 2026 Summer Being 'Like the Japanese Archipelago is Inside a Giant Steamer'

The trend of high temperatures in summer has been accelerating in recent years. In the approximately 150-year history of observation, the highest domestic temperature of 41.8℃ was recorded in Isesaki City, Gunma Prefecture last year. It was a summer of records, with Tokyo having a record high of 29 extremely hot days. Moreover, recently, the heat continues into September and October like an extension of summer. Considering the trends of recent years, there will likely be periods of record-breaking extreme heat in various places this summer that will rewrite previous numbers. Combined with high humidity, it seems that the Japanese archipelago will have a summer like being inside a giant steamer.

The key to surviving the harsh summers of recent years is not to carry fatigue over to the next day.

Extreme heat leads to a decrease in concentration, judgment, and ultimately job performance, and also increases the risk of heatstroke. First, before the real heat sets in, let's promote 'heat acclimatization' to get the body used to the heat by exercising and taking baths. And the key to surviving the harsh summers of recent years is not to carry fatigue over to the next day. Lack of sleep due to tropical nights, which are increasing year by year, is a great enemy. Please try to reset your fatigue with good quality sleep by using the air conditioner wisely.

Meteorologist Masaaki Masuda

Born in Koka City, Shiga Prefecture in 1977. TBS TV and Radio weathercaster.

Obtained the meteorologist qualification while in university and appeared on news programs of commercial key stations as a student forecaster.

While working as a weathercaster, he has long been in charge of advising companies, local governments, and individuals on weather. He has also served as the weather person for the tournament headquarters at the summer high school baseball tournament at Koshien. Hoping that more people will know the fun of weather and how to use weather information well, he actively gives lectures and visiting classes for children all over the country.

[Kao Representative Comment] Ai Terayama, Personal Health Business Division, Kao Corporation

This survey once again highlighted that the summer heat and humidity have a serious impact on the work and human relationships of people working outdoors. What is noteworthy is the reality that 40% of people do not take a bath because 'it's hot' even though they feel fatigued. If you welcome the next day with fatigue accumulated in your body, it will lead to a further decrease in concentration and judgment, and increase safety risks. In order not to carry over this 'sticky fatigue*' to the next day, it is important to properly recover from fatigue by taking a bath on the same day.

'Bub Medicure Cooling Cool' lowers the psychological hurdle to bathing this summer. High-concentration carbonation*1 promotes blood flow, enhances the bathing effect, and is effective for fatigue, stiff shoulders, and lower back pain. Because it contains a high amount of menthol (cooling ingredient)*1, it is refreshing both during and after the bath. I hope you will definitely experience fatigue recovery through a refreshing bath, especially in the hot summer.

About Bub Medicure Cooling Cool

For the painful feeling of summer fatigue* of busy modern people. Refreshing after the bath.

Your usual bath turns into a high-concentration carbonation*1 bath!

Enhances the bathing effect and is effective for fatigue, stiff shoulders, lower back pain, and sensitivity to cold.

● Comfort of 10 times the number of bubbles of Bub*1

● Contains active ingredient alum*3

● High amount of menthol (cooling ingredient)*1 Refreshing after the bath!

● Refreshes even your mood Lemongrass scent

● Water color: Fresh blue (colored transparent)

[Quasi-drug] Sales name: Bub Medicure Ca1

* Feeling of fatigue

*1 Comparison target: Our Bub Cool Refreshing Mint Scent *3 Aluminum potassium sulfate