Ms.Mitchell&HeatStress

Questions for Dr. Mitchell
media type="custom" key="179245" (1) At what point does your body "over heat"? Everybody's body is different, however, text book will tell you that heat exhaustion temperatures range between 97-104 and that > 104 enters exertional heat stroke (all temperatures are recommended to be rectal). However, whenever anyone feels any signs of overheating is when your body has overheated regardless of what the thermometer says.
 * Heat Exhaustion <104 = over-heating but it is not life threatening (red, sweaty)
 * Heat Stroke > 104 you may have brain damage, the body's cooling system in the brain has shut down

(2) What are the signs of over-heating? Signs of over-heating at the heat exhaustion level can include a normal or elevated body temperature, dehydration, dizziness, lightheadedness, syncope (FAINTING), nausea, diarrhea, decreased urine output, persistent muscle cramps, pallor (PALE), profuse sweating, chills, cool/clammy skin, intestinal cramps, urge to defecate, weakness, hyperventilation. Signs of over-heating at the exertional heat stroke level can include most of the above plus drowsy, irrational, confusion, irritability, emotional instability, hysteria, disorientation, staggering, seizures, loss of consciousness, coma, tachycardia (FAST HEART RATE)

(3) Why does gatorade have salt? Why do you need to replace salt? Sports drinks include salt for a couple of reasons, to stimulate thirst and to help replace the electrolytes (IONS, ATOMS WITH A CHARGE BECAUSE THEY LOST OR GAINED AN ELECTRON, THE NERVOUS SYSTEM USES ELECTRICTY FROM ELECTROLYTES TO TRANSMIT SIGNALS) (mainly sodium and potassium) lost through sweating. they also contain sugar to help bring back up blood sugar levels.

(4) How does the nervous system respond to heat stress? Your brain is the thermostat (Can tell temperature maintain it) and the CNS (Central Nervous System: Brain and Spinal Cord) helps in temperature regulation which becomes overwhelmed when in heat exhaustion/stroke due to excessive endogenous (INTERNAL) heat production or inhibited heat loss in hot conditions and can progress to complete thermoregulatory system failure (CNS SHUT DOWN). Overheating may induce malfunction of the temperature control center of the brain, circulatory failure (Blood stops flowing), or endotoxemia (CNS shut down, circulatory system shut down) which is a combination of the previous two.

(5) Is there any temperature that is unsafe for exercise? Guidelines exist for what is too hot to exercise and what is not, but in areas such as the south no one would ever be allowed to be outside during July, August, September if this were strictly adhered to. Therefore, such as in the past couple of weeks...school boards, NCAA, TSSAA will take it upon themselves to put out some mandatory regulations. Overall, I think you just have to be smart about it and practice early or late and avoid the heat of the day.

(6) What actions can be taken to prepare for exercising in extreme heat? Acclimation (ADJUSTING TO IT: SWEAT MORE, LOSE LESS SALT) is one of the most important things to exercising safely in the heat. Other good measures include being in shape, proper diet, and excellent hydration.

(7) If a person feels symptoms of heat stress, what should they do? If someone feels symptoms of heat illness ideally they should stop activity, get in a cooler environment, get fluids in them, and rest.

(8) How do you recommend avoiding overheating? Heat illness are a completely preventable injury with proper hydration, good acclimation back into the heat, plenty of breaks during practices, enough rest time in between practices, good nutrition, and a constant watch over participants. If you have high risk athletes you can have them weigh in before and after activity to make sure that they have not loss more than 2-3% or their total body weight from sweat.

(9) What is the most common reason for bad performance in athletes health wise? Bad performance in athletes health wise is usually lack of sleep, lack of proper diet, lack of proper hydration, or another unrelated injury (pulled muscle for example). At this age the mental aspect is usually a key factor in bad performance (performed bad on test, girlfriend/boyfriend problem, problems at home, etc.)

(10) Are there any long term consequences to overheating? Long term consequences of over heating in the most severe of cases is obviously death. However, this is not the norm and fortunately doesn't happen very often. In most cases of heat illness there are no true medical long consequences of over heating, although some research will say it makes a person more likely to have it occur again. However, the internal organ functions and things of that nature in most heat illnesses are not permanently damaged.

(11) Why do you faint when you overheat? What causes your circulatory system to become weak? Lack of blood to the brain will cause one to faint, this usually occurs do to a dip in ones blood pressure which can occur from extreme heat (LOSING WATER MEANS LESS BLOOD LESS PRESSURE). I also look at a person fainting in the heat as a protective mechanism because they have now stopped physical activity possibly preventing a more serious heat illness. (if i prove that one in the future i will let you know!)

(12) Why do you start breathing faster and harder? Breathing mechanisms change due to the stress the body is experiencing due to the heat. The internal organs have more stress put on them. However, a lot of times i think people make this particular symptom worse because of fear and panic because they don't feel well. I am not dismissing the true physiological reasons by any means, just pointing out a different cause.