During exercise in the heat, the thermoregulatory system impacts performance in an athletic population. Increased in core body temperature could lead to development of heat-related illnesses and impair physical performance. To facilitate heat loss and optimize performance during exercise in the heat, various cooling strategies, including cold water immersion and wearable cooling devices have been previously explored. Although whole body cooling by cold water immersion is considered to be the most effective way to reduce core body temperature, this cooling method would not be feasible for athletes during practice or competition. Therefore, previous studies strongly recommended neck cooling during exercise because of the rate of heat dissipation through the large blood vessel and accessibility compared to other body part. Furthermore, multiple studies reported that the neck cooling could improve aerobic performance (i.e. running distance and time). In addition to physiological changes, human prefer to be cool in the neck region as well as the face in hot environment. Thus, local cooling of the neck is efficient way to reduce thermal discomfort during heat exposure. The novel neck cooling collar device (NeuroRescue Inc., Lafayette, LA) used in the current study may be able to produce powerful effect of conductive cooling, which result in improving performance and also reduce thermal discomfort during exercise in the heat.

While this neck cooling collar would assist athletes in improving sports safety and performance by decreasing skin temperature around the neck, the effectiveness of this neck cooling collar on core temperature was not examined at this point. Moreover, other physiological and perceptual changes are important to assess along with changes in core body temperature. Therefore, this study aims to examine how internal body temperature, heart rate, perceptual measures, and athletic performance are affected by the novel neck cooling collar during exercise in the heat.

Inclusion Criteria:

1. Physically active (at least 30 minutes of exercise 3-5 days per week) male
2. been cleared by the medical monitor for this study
3. Have a VO2max >45ml/kg/min

Exclusion Criteria:

1. Have a current musculoskeletal injury that would limit their physical activity or preclude the participant from walking, jogging, running, sprinting, or cutting.
2. Chronic health problems that affect your ability to thermoregulate (disorders affecting the liver, kidneys or the ability to sweat normally)
3. Fever or current illness at the time of testing
4. History of cardiovascular, metabolic, or respiratory disease
5. A family member died for no apparent reason, had a heart attack, died from heart problems, or sudden death before the age of 50
6. Current musculoskeletal injury that limits their physical activity
7. Currently taking a medication that is known to influence body temperature (amphetamines, antihypertensives, anticholinergics, acetaminophen, diuretics, NSAIDs, aspirin)
8. Are a female. Due to the internal body temperature gradient that accompanies the menstrual cycle, inclusion of females may not provide the most controlled internal body temperature data for this study.
9. Have a history of heat related illness
10. Throat or gastroesophageal diseases including gastroesophageal reflux disease (aka, GERD) or difficulty swallowing
11. Have any allergies or adverse reactions to the cold (e.g. Cold Urticaria, Raynauds Phenomenon/Disease, or cryoglobulinaemia)
12. Any COVID-19 related symptoms including fever, cough, shortness of breath or difficulty breathing, gastrointestinal discomfort (nausea, vomiting, and/or diarrhea), repeated shaking with chills, muscle pain (unrelated to exercise), headache, sore throat, new loss of taste or smell, congestion or runny nose.
13. Participant with clinical diagnosis of COVID-19 infection or positive result on a COVID-19 test due to concern about cardiac complications.