Scientific Research

 

Introduction - Many devices designed to help prevent heat illness are short lived and/or ineffective. Also, the lack of portability of cooling devices and systems inhibits widespread acceptance and use by athletes and the public at large.  While advancements have been made in the field of athletics, e.g., GPS technology used to measure fatigue and fitness, the cooling of athletes often relies on decade’s old practices, including the use of wet towels and soaked sponges.  Future research should focus on affordable, portable and effective devices such as Thermonator Headbands, which provide for rapid and sustainable cooling of athletes by cooling the arterial blood entering the brain. Among athletic trainers and sports performandce analysts, there is consensus that Thermonator Headbands cool down athletes and helps them recover from heat fatigue more quickly.

Problem – During intense physical activity, athletes are routinely exposed to a variety of environmental conditions that can alter judgment and physical performance and even result in death. A high core body temperature is defined as 104°F, which could result in dry skin, nervous system dysfunction, mental confusion, delirium, convulsions, and unconsciousness. The principal cause of heat stroke is failure of the hypothalamic temperature regulatory system. The failure of the hypothalamus to regulate body temperature results in the body’s inability to dissipate heat, which induces an immediate excessive increase in core body temperature.  

Studies - Military Medicine, 2008. Excessive exposure to heat with impeded heat removal through the cerebral circulation can lead to accumulation of heat in the brain.  When heat accumulation exceeds removal in the brain, temperatures may exceed 40°C (104°F), potentially impairing the ability of soldiers and athletes to sustain normal work intensity. With ongoing exertion, there may be restricted availability of glucose in the brain, invoking central fatigue, which is closely associated with reduced (20%) cerebral blood flow. Continued bouts of high intensity activity impose strains on the cardiovascular and locomotive systems and also the brain, ultimately leading to increases in the perceived effort in soldiers and athletes..  Brain temperature is a critical factor affecting motor activity during exercise in hot conditions. During exercise under high temperatures, there is impaired ability to remove heat from the blood and there is estimated to be 72% greater heat production in the brain.  The principal cause of heat stroke is failure of the hypothalamic temperature regulatory system.  A typical treatment for a victim of heatstroke is to provide rapid cooling to reduce the core body temperature. Local cooling of the carotid arteries during high-intensity exercise has been found to attenuate increasing brain temperatures, reduce core temperatures, and improve perceptions of physical efforts.  The cooling of the neck region and head may attenuate heat-related illnesses during strenuous physical effort in hot environments and may improve physical performance. A typical treatment for someone suffering from heatstroke is to provide rapid cooling to reduce the core body temperature. The head and neck are some of the most efficacious regions of the body to cool to prevent heat illness and injury.

The Department of Exercise and Sports Sciences at Copenhagen University, 2012. Results of a series of studies concluded that when athletes become exhausted in hot conditions, it isn’t directly related to muscle fatigue, but rather the result of fatigue of the central nervous system (central fatigue).  Central fatigue is a form of performance impairment that affects the brain rather than the muscles. When central fatigue develops, the brain becomes unable to send enough signals to the muscles to maintain optimal muscle activation, resulting in impaired performance and decreased muscle strength. When central fatigue kicks in even the best-trained athlete with maximum willpower is rendered helpless.  Since the brain is dependent on the temperature of the blood entering the brain, as core temperature rises, either as a result of the ambient temperature or due to hard physical activity, the blood temperature increases, and that disables the brain’s cooling system.  A hot brain leads to a fatigued body.

Brad Stulberg, Your Brain in Extreme Heat, 2016.   The hypothalamus gland, located just above the brain stem, is hyper sensitive to changes in core temperature.  When temperatures rise, the athlete’s body is forced to work much harder than normal.  During prolonged exercise in heat, if an athlete’s core temperature reaches 99.5°F, which is nearly a full degree above your baseline core temperature of 98.6°F, the hypothalamus determines it’s time to lose heat and the brain reacts by opening up blood vessels near the skin and routing blood to the periphery, where it can cool. As an athlete continues to exercise in an environment that feels warmer than 99.5 - from the air itself, but also humidity, wind, and sunlight - the body struggles to shed heat and the temperature of the blood entering the brain continues to rise.  This is the brain’s way of telling the body to stop generating so much heat.  Continuing to exercise, especially in environments that feel hotter than 104°F, puts the athlete at risk for more serious illness and injury.  As the brain continues to overheat, the central nervous system starts to go haywire (central fatigue), leading to confusion, agitation and dizziness, which are all signs of heat stroke, signaling it’s time to seek medical attention immediately.

ScienceNordic, Hot brains impair athletic performance, 2012. Central fatigue is a form of performance impairment that affects the nervous system (the brain) rather than the muscles. When central fatigue develops, the brain becomes unable to send enough signals to the muscles to maintain optimal muscle activation, and that will eventually impair performance.  Central fatigue can arise if the brain becomes overheated. The brain temperature depends on the metabolic rate of the brain and the amount of heat entering versus leaving the brain. The brain is therefore dependent on the temperature of the arterial blood entering the brain.  But when the body core temperature rises, either as a result of the ambient temperature or due to hard physical work, the blood temperature increases, and that disables the brain’s cooling system.  When athletes became exhausted in hot conditions, it isn’t directly related to muscle fatigue. The fatigue is a result of fatigue in the central nervous system rather than in the muscles.  While not conclusive, it’s believed the brain’s own temperature that probably causes central fatigue.  Hot brains impair athletic performance.

Conclusion - Accepted among athletic trainers for decades has been the practice of using wet towels and water filled sponges to cool athletes. Like other means of providing cooling relief these methods provide short relief at best.  Even today, with remarkable advancement in safety issues and athletic performance, the use of wet towels and water filled sponges remain a steadfast approach to cooling athletes.   Emerging knowledge points to the critical importance of cooling the blood entering the brain. The hypothalamus gland, located just above the brain stem, is hyper sensitive to changes in core temperature.  During exercise under high temperatures, there is impaired ability to remove heat from the blood.  As core temperature rises, either as a result of the ambient temperature or due to hard physical activity, the blood temperature increases, and that disables the brain’s cooling system. Central nervous system fatigue (central fatigue) is a form of performance impairment that affects the brain.  When central fatigue kicks in, even the best-trained athlete with maximum willpower is rendered helpless. Hot brains prevent normal cognitive functioning, athletic performance and work production.  Studies suggest that the cooling of the neck, specifically the right and left carotid arteries, and the brain, which has the highest concentration of blood vessels in the body, may reduce heat-related illnesses during strenuous physical activity and improve physical performance.  Thermonator Headbands cool the blood as it flows to the brain via the carotid arteries on the sides of the neck and pulse points found on the head.  Among athletic trainers and sports performandce aanlysts there is consensus  that Thermonator Headbands help cool down athletes and helps them recover from heat fatigue more quickly.