Environmental Considerations Flashcards
Heat Stress
Is preventable, the body must be able to dissipate heat to maintain homeostasis
Metabolic Heat Production
normal metabolic function results in production of heat
Conductive Heat Exchange
physical contact with objects resulting in heat loss or gain
Convective Heat Exchange
body heat can be lost or gained depending on circulation of medium
radiant heat exchange
sunshine will cause an increase in temperature
evaporative heat loss
lose 1 quart of water per hour for up to 2 hours
Humidity effects
- relative humidity of 65% impairs evaporation
- relative humidity of 75% stops evaporation
Preventing Heat Illness
- use common sense and precaution
- hydration
Dehydration
occurs when 2% of body weight is lost in fluid
- will impair cardiovascular and thermoregulatory
Signs of Dehydration
- thirst
- dizziness
- dry mouth
- irritability
- excessive fatigue
- possible cramps
How do you treat an athlete with dehydration?
- move them to a cool environment
- begin re-hydration
- return to activity only after fluid wt. loss has been regained and symptoms cease.
Fluid & Electrolyte Replacement
- body requires 2.5 L of water daily when engaged in minimal activity
- adult will typically lose about 1.5L/hour
NCAA Mandated Guidelines (FB)
Day 1: only one practice a day (equipment restrictions)
Days 1 & 2: Helmets only
Days 3 & 4: Helmets and shoulder pads only
Day 5: Full pads
After day 5: twice a day every other day*
How do you identify susceptible individuals?
- athletes with large muscle mass
- overweight athletes
- young or elderly
Weight records
- measured for the first two weeks
- A >2% loss of body weight during activity is a health risk
- remove from activity until normal weight returns/is hydrated
Monitoring Heat Index
monitor heat, sunshine, humidity
Wet bulb globe temperature index
- dry bulb (standard mercury)
- wet bulb (thermometer with wet gauze, swung in air)
- black bulb (black casing that measures radiant heat)
Heat Illnesses
- Heat rash
- Heat Syncope
- Heat Cramps
- Exertional Heat Exhaustion
Heat Rash
- prickly heat
- red, raised rash
- result of being continuously wet from un-evaporated sweat
- generally in areas covered with clothing
How to treat heat rash
keep skin dry
towels
powder
Heat Syncope
- standing in heat for long periods of time
- fatigue
- overexposure to sun
- dizzy
- fainting
- caused by peripheral vasodilation or pooling of blood in extremities
- get athlete to cool, dry area, consume fluids, elevate legs
Heat Cramps
- painful muscle spasms due to excessive water loss and electrolyte imbalance
- result of overexertion in a hot environment
- occurs primarily in calf and abdomen
Exertional Heat Exhaustion
- result of inadequate fluid placement
- unable to sustain adequate cardiac output
Signs of Exertional Heat Exhaustion
profuse sweating pale skin mildly elevated temperature dizziness nausea, vomiting or diarrhea hyperventilation muscle cramping loss of coordination
Heat Exhaustion
- may develop heat cramps
- may become faint and/or dizzy
- core temperature will be less than 104 degrees***
treatmetn for heat exhaustion
- fluid ingestion
- place in cool environment
- remove excess clothing
- monitor vital signs
- must be cleared by a physician
- can progress to heat stroke if not treated
Exertional Heatstroke
serious life-threatening condition
- breakdown of thermoregulatory system
- sudden collapse
- flushed hot skin, minimal sweating
- shallow breathing
- strong rapid pulse
- core temperature of > 104 degrees
How to treat Heat Stroke
- strip clothing
- sponge with cool water
- use ice packs
- call 911/transport to hospital immediately
- cool first, transport second
- most likely be unconscious
Cold water immersion
- dunk tank should be 36-68 degrees
- goal is to reduce the core temperature to at least 102 degrees
- survival rate of athletes treated with cold water immersion is 100%
Malignant Hyperthermia
- rare, genetic muscle disorder causing hypersensitivity to anesthesia and extreme exercise in hot environment
- athletes will complain of muscle pain after exercise
- elevated temperature 10-15 mins after exercise
- disqualification from hot, humid events
Acute Exertional Rhabdomyolysis
- sudden catabolic destruction and degeneration of skeletal muscle
- occurs during intense exercise in heat/humidity
Signs of acute exertional rhabdomyolysis
- gradual muscle weakness, swelling, pain, dark urine, renal dysfunction
- can lead to sudden collapse, renal failure and death
- associated sickle cell trait
exertional hyponatremia
- fluid/electrolyte disorder resulting in abnormally low concentration of sodium in blood
- caused by ingesting too much fluid before and after exercise
signs of exertional hyponatremia
- progressively worsening headache, nausea, vomiting
- swelling of hands and feet, lethargy, apathy or agitation
- low blood sodium
Athletes who intentionally lose weight
- predispose themselves to heat related injuries that could create life-threatening situations
- weight loss should not be accomplished through dehydration
- NCAA est. guidelines for weight loss in wrestling
