Extreme Heat Affects Not Only Humans, but That Animal Too

Japan has again been hit by severe heat this summer, including five consecutive days of "extremely hot days" exceeding 40°C. The increasingly harsh summer heat affects not only humans but also various animals, and zoos have introduced measures such as installing shade nets and mist sprayers. Among animals, horses are particularly susceptible to heat, partly because their large muscle mass makes it easy for heat to build up. Since horses have long been deeply connected to Japanese culture and frequently appear in tourism settings such as traditional events and horse racing across the country, various considerations and measures are being advanced in these situations as well. This column introduces two examples.

1. Spreading Out the Timing

In response to the severe summer heat of recent years, some traditional events that were once summer highlights are reconsidering when they are held. The Soma Nomaoi, held in the Soma region of Fukushima Prefecture, changed its schedule in 2024 from "the last Saturday, Sunday, and Monday of July" to "the last Saturday, Sunday, and Monday of May." As the reason, the executive committee explained that at its general meeting in February 2023 it had decided to "consider changing the schedule in light of the effects of recent global warming on people and horses," and that after two horses died at the Soma Nomaoi held in July, it changed the schedule the following year.¹⁾ Despite the addition of various measures, it remained difficult to prevent heatstroke—this case illustrates just how extreme the recent heat has become.

2. Spreading Out the Time of Day

Spreading out the time of day, which has been spreading as a measure against overtourism, is also drawing attention as a heat countermeasure, and the Japan Racing Association (JRA) has introduced measures in consideration of the burden on people and horses. In 2024, for the post times of the second Niigata race meeting, the JRA implemented expanded racing hours by moving back the final race and suspending racing during the hottest hours, setting a suspension period from around 11:30 a.m. to around 3:10 p.m.²⁾ Expanded racing hours are also being implemented in 2026, with the period extended from two weeks to six weeks and the venues expanded to two locations—Chukyo Racecourse in addition to Niigata Racecourse. The extension of the implementation period to six weeks can be seen as a response to recent climate change, in which hot periods are lengthening and a shift toward "two seasons" is progressing.

This time we focused on examples involving horses, but the increasingly hot summers of recent years are a harsh season for people, too. In addition to measures that ease the heat, such as parasols and uchimizu (sprinkling water on the ground), we can reduce the burden of heat by adopting a perspective of avoiding the heat itself—for example, by spreading out the timing and time of day of our travels. Let's get along well with the heat and enjoy a comfortable summer trip, each in our own style.

<References>
1) Soma Nomaoi Executive Association, "Regarding the Change to the Soma Nomaoi Schedule"
https://cms.soma-nomaoi.jp/wp-content/uploads/2023/11/0a49a6bc82cafc457bd658d462ac2cd9-2.pdf
2) Japan Racing Association, "New Heat Countermeasures in the 2024 Racing Program"
https://www.jra.go.jp/keiba/program/FY2024/pdf/taisaku.pdf