How your body cools down
The body uses four mechanisms of heat exchange to maintain homeostasis: conduction, convection, radiation and evaporation. A sweating dysfunction however – whether as a result of medication, autonomous nervous system dysregulation or a worsening of neurological symptoms – means that no evaporation heat loss can take place.
This drastically heightens the risk of developing heat fatigue or heatstroke, as well as other issues including muscle spasms, heat-induced seizures and nausea; common experiences for people with Spinal Cord Injuries, Multiple Sclerosis, Cerebral Palsy and other neurological conditions which impair the body’s ability to sweat.
Having to “just deal with” overheating and warm environments can, therefore, be dangerous if precautions aren’t taken. This becomes even more problematic during exercise.
Former European champion and double paralympian wheelchair rugby player Michael Kerr said that overheating is one of the biggest obstacles for him while training and playing in tournaments due to his spinal cord injury.
“I find overheating very, very uncomfortable. It’s also very hard to control. It limits what I can do,” he said. “It also makes me feel very unpleasant when exercising or in a game – which is very distracting when playing rugby. After becoming very hot, it is very hard to get my body back to a normal temperature.
For example, if I’m playing an intense game, it often takes the best part of an hour to get back to a normal temperature. Say I’ve got two or three games in a day, my body temperature is constantly changing like a seesaw. The day is made up of heating up and cooling down.”
All of this is why we here at WheelAir focus on preventing overheating altogether. Or rather, we want to encourage ‘pre-cooling’. This means the reduction of body temperature before exercising to slow down the process of reaching a critical limiting core temperature which contributes to fatigue.
Lots of academic research has focused on pre-cooling and its effect on sport performance for those with a Spinal Cord Injury (SCI). Once the overheating process has started, it will take much longer to cool back down. Studies have shown that once exercise has commenced, the temperature of the body will keep rising for a certain period, even after exercise has stopped.
This reflects our own research. When using the WheelAir after exercising for 30 minutes, the body was only able to cool down by 3.16% within three minutes. Whereas, there was a 7.14% decrease in temperature when using the WheelAir before exercising. This again reiterates the need for pre-cooling, adjusting fan speeds and generally avoiding heat build-up, whether exercising or just out and about.
Since he started using his WheelAir for pre-cooling, Michael feels much more comfortable and in control of his body temperature during exercise.
“Before the WheelAir I was mainly spraying my with water and using ice packs to keep cool whilst playing,” he continued. “These solutions do make you feel better but it’s like a short hit – it doesn’t stop me being hot, it just makes me feel cooler and more pleasant.
“My body feels noticeably cooler after using the WheelAir. The main benefit is you can start pre-cooling any time and no-one would even know. For example, before you start training, or before you get out in the sun, you can turn it on.
“It certainly has improved my athletic performance! But the WheelAir has been great not just for when I’m playing sport, but in everyday life too.”