HEAT CONSIDERATIONS

Hyperthermia                                                                                                                        ]

Medical term for heat illness

  • Deaths due to heat illness

  • Sports: Most prevalent in distance runners and high school football

  • Regardless of how conditioned the athletes, use EXTREME caution when exercising in hot, humid weather

  • is preventable

Displacing Body Heat                                                                                                            ]

Evaporative Heat Loss

  • Sweat evaporation

  • humidity makes it difficult for sweat to evaporate, making it difficult to cool down

  • Blood carries your body heat

    • vasodilation of blood vessel at the surface of the body

    • Heat is transferred into the “water” in your sweat glands

    • those water molecules are squeezed through your pores = sweat

    • sweat is evaporated off your skin and pulls heat from the body

    • Resulting in bodily heat loss

  • air MUST be free of water for evaporation to occur

    • relative humidity > 65% impairs evaporation

    • relative humidity > 75% stops evaporation 

Displacing Body Heat                                                                                                            ]

Heat Cramps

  • Extremly painful muscle spasm

  • most commonly occurs in calf and hamstring but can occur in any muscle

  • occurs due to excessive loss of H2o and electrolytes (Na, K, Ca)

  • Prevention = well hydrated with electrolyte replacement, good physical shape, acclimatization

  • Treatment = removal from activity, ingest water/ electrolytes, cool down (shade), stretch cramped muscle, ice bag/ice massage (descreases elesticity)     

    • not too much, for the muscle is contracted   

Heat Exhaustion

  • Result of inadequate fluid replacement, hot climate, and body overheating

  • Symptoms: Nausea, headache, dizziness, fainting (hyperventilation), weak rapid pulse, low blood pressure, profuse sweating, pale wet skin

  • normal core temperature < 104°

    • most efficient way to measure is through rectal thermometer

  • When dehydration occurs: Blood volume decreases, blood pressure decreases, pulse weakens 

  • Treatment = removal from activity, ingest water/ electrolytes, cool down (shade, AC, remove excess clothing), monitor athlete until fully recovered (gradually return to play), if athlete deteriorates, refer to hospital

Heat Stroke

  • very serious condition

  • LIFE-THREATENING (call 911)

  • COOL FIRST, transport second

  • signs/ symptoms: nausea, rapid pulse, profuse/ lack of sweating, hot/ dry (potentially) skin, core temperature > 105°, unconscious, sever disorientation

  • treatment

    • call 911

    • drastic measures must be taken to cool athlete (remove equipment/gear, immerse in ice bath, then transport to hospital)

    • then transport to hospital (do not transport until core temperature drops)

    • final symptom = death

Prevention

  • Hydration → should begin any activity well hydrated (hydrating during the 24 hours prior to activity, truly 3 days before, urine should be light yellow in color, weighing before/ after practice, 1-2 lbs loss in normal) REPLACEMENT OF FLUIDS AND ELECTROLYTES

  • Gradual acclimatization

    • 10-14 day process

    • get accustomed to excercizing in heat 

    • graded intensity changes

    • equipment restrictions

    • frequent rest breaks during practice

  • Identifying susceptible individuals

    • athlete with high BMI (out of shape)

    • death from heat stroke increases 4:1 as body wight increases

    • adjust practice times

Wet Bulb Globe Temperature Monitor

  • Heat, sunshine, and humidity must be monitored closely

  • monitors radiate temp (sun)

  • air temp

  • humidity

  • modifications

Lightning

  • MOVE INDOORS

  • AVOID: large trees, metal poles (flag/light), standing water, pools, showers, telephones (landlines), metal objects!

  • feeling electrical charges in the air

  • lightening = generally accompanied by thunder

  • guidelines

    • flash-to-bang method (see lightening → count until you hear thunder → divide by 5 to calculate distance, 30/30 rule → 30 seconds, 30 minute wait)

    • weather bug (phone app)

High Altitude

  • altitude increases, less oxygen

    • results in decrease in performance

  • body compensates with tachycardia and hyperventilation

  • responses due to having fewer RBC than necessary to adequately capture available O2

  • acclimatization

    • RBC increase = decrease in bodies compensations 

  • altitude illness symptoms

    • headache, nausea, vomiting, sleep disturbance, dypsnea

    • use oximeter to measure