Rolling Stone: Can We Survive Extreme Heat?

In this 2019 article in Rolling Stone, writer Jeff Goodell poses an existential question of our planet: Can we survive in extreme heat. He points out that humans have never lived on a planet this hot, and that we’re totally unprepared for what’s to come.

The article was written at a time when temperatures at Phoenix’s Sky Harbor International Airport had reached 115 degrees Fahrenheit or higher.  Hundreds of flights were being delayed or cancelled due to the fact that heavily laden passenger aircraft couldn’t generate enough lift to take off in such thin, hot air.  Phoenix is already located in a hot region and the urban heat island effect can make the city as much as 21 degrees hotter than surrounding areas. How will humanity cope with a climate that is heating up everywhere?

Read the full article here.

Wearing a Cooling Vest During Half-Time Improves Intermittent Exercise in the Heat

This 2019 study, from researchers at Kobe University and University of Tsukuba in Japan, examined how endurance and intermittent exercise performances are impaired by high ambient temperatures.

The purpose of this study was to investigate the effect of wearing cooling vests which cooled torso and neck area of athletes during half-time (HT) on intermittent exercise performance that imitated intermittent athletic games. This kind of ‘intermittent effort’ simulation best describes sports like American football or Rugby in which the actions is stop and start, throughout a game.  The results of the eperiment indicated that wearing a cooling vest during breaks (such as half time) significantly improves intermittent exercise performance in the heat with decreased neck and mean skin temperature and improved subjective responses.

You can access the full study here.

Cooling Vests Worn During Active Warm-Ups

This study, in the Journal of Applied Physiology from 2004, explored whether a cooling vest worn during an active warm-up enhances 5-km run time in the heat. Seventeen competitive runners (9 men and 8 women) completed two simulated 5-km runs in a hot, humid environment (32°C, 50% relative humidity). The athletes completed active warm-ups during which they wore either a T-shirt or a cooling vest. Results showed the 5-km run time was significantly lower (by 13 second) for those who warmed up in a cooling vest, with a faster pace most evident during the last two-thirds of the run.

You can access the study here.

Effects of Pre-Cooling Procedures

How can cooling garments help athletes perform at the top of their games?

This study, from the European Journal of Applied Physiology in 2007, explored whether pre-cooling procedures improved both maximal sprint and sub-maximal work during exercise. In the tests, nine male rugby players performed a familiarization session and three testing sessions of a 2 × 30-min intermittent sprint protocol. This protocol consisted of a 15-m sprint every min separated by free-paced hard-running, jogging and walking in 32°C and 30% humidity.

The study found that over greater distances covered in workouts, participants who used ice baths or cooling vests had increasingly lower heart rates, lower sweat loss, and more thermal comfort overall during their activities.

The study can be accessed here.