Hello, everyone.

This is Enta.

It's been a string of hot days, hasn't it?

Are you wearing an air-conditioned suit?

Shorts are all the rage these days!

I've been seeing them quite often in private construction projects for the past few years.

It seems to be gradually gaining traction, as even major companies are surprisingly granting permits for public works projects.

I was wondering if our work uniforms might be used as shorts, so I did some research.

That turned out to be an unexpected result, lol.

One of our employees was doing it, so I asked them about it, and they said, “It’s nice and cool.” Haha.

1. Assumptions for Comparison

It seems that whether or not it’s cool depends on the following factors.

Breathability (Airflow)

Heat Dissipation (Radiation, Convection, Evaporation)

Evaporation Efficiency of Sweat

Preventing an Increase in Skin Surface Temperature

Shorts plus leggings have a structure with “little air space between the skin and the fabric,” whereas regular pants (work pants) have a structure with “loose-fitting fabric and air space.”

2. Experimental Data and Research

• Occupational Medicine Research (Japan: Ministry of Health, Labor and Welfare; University of Occupational and Environmental Health)
  According to a comparative experiment on the WBGT (heat index) of work clothes, breathability and the presence or absence of airflow inside the garment strongly influence the perceived temperature; it appears that even with the same material, “tight-fitting spats are more prone to trapping heat.”
• Findings from Sports Science
  Compression tights, which are used in activities such as marathon running and soccer, are designed to “support muscles and reduce fatigue,” but are considered less breathable than regular lightweight shorts (according to a paper published by the Japanese Society of Physical Education in the field of exercise physiology).
• Research on Air-Conditioned Workwear for Construction Sites (National Institute of Occupational Safety and Health, 2020)
  For air-conditioned clothing that draws in airflow, “air circulation inside the pants is considered important,” and loose-fitting pants are said to enhance the cooling effect. It has been pointed out that leggings may hinder the effectiveness of air-conditioned clothing.

Practical Conclusions for the Field

• Shorts + Leggings
  → Although sweat evaporates at the surface, the tight fit of the spats causes heat to build up easily. This tight fit hinders heat dissipation, which is a disadvantage during long work sessions.
  → While effective for sports (short duration, high intensity), it tends to feel hot during long hours of work on construction sites.

• Regular pants (breathable)
  → An “air layer” forms between the fabric and the legs, allowing for heat exchange with the outside air. The combination of the air layer and airflow makes it easier to dissipate heat, which is an advantage. Works perfectly with climate-controlled clothing.
  → Since long pants allow airflow from windbreakers and air-conditioned clothing to circulate, they keep you cooler.

They look stylish and cool, but since a larger air pocket actually keeps you cooler, pants seem to be a good way to prevent heatstroke.

Short spandex shorts may look cool, but it turns out that while the person wearing them may feel cool, the data actually shows they aren't...

It's the placebo effect, isn't it?

Even if it doesn't work scientifically, it all comes down to the person's motivation, huh? lol

I think it's also important to create a work environment where people feel comfortable.

See you later.