What is heat stress?
Heat stress occurs when the body’s internal core temperature rises above its normal level. As core temperature rises, so does the risk of heat stress. Core temperature greater than 39°C is dangerous and can lead to heat stress.
Heat stress factors include air temperature, humidity, radiant heat, air movement, the physical demands of work, the clothing worn and what kind of work is performed. The dangers of heat stress range from heat rash, heat cramps and heat exhaustion to potentially fatal heat stroke.
How to avoid heat stress
- Use the six Rs of rehabilitation
- Rest
- Rehydration – fluid intake (hydration)
- Restoration – active cooling
- Rx – medical monitoring and treatment
- Relief – from extreme climatic conditions
- Refuelling – where required
- Train personnel in proper rehab procedures
- Use active cooling and forearm immersion to keep cool.

The science behind core cooling
- The Royal British Navy (1996) demonstrated the effectiveness of forearm immersion in water temperatures ranging from 10 to 30°C to effectively lower core body temperatures of shipboard firefighters.
- Defence Research and Development Canada (DRDC) (2003) also studied the effects of heat stress on firefighters while wearing protective clothing.
- The DRDC determined that forearm immersion was the most effective means of lowering core temperature.
- Forearm immersion was more effective than a misting fan and does not lose effectiveness as humidity increases.
- The DRDC study determined the need to ‘actively cool’ after the second cylinder change (30-minute bottles) and after each subsequent cylinder change.

How the Kore Kooler Rehab Chair works
The Kore Kooler Rehab Chair relies on direct contact of the skin with a large volume of ambient temperature water (10–30°C). The many blood vessels running through the arms and hands, located close to the skin’s surface, make this technique an excellent method to reduce core temperatures. Heat moves through the blood vessels and skin into the cooler water then the cooled blood returns to the heart and pumps throughout the body.
For more information, go to www.korekoolerchair.com