Chapter 9: Understanding the Potential Dangers of Adverse Environmental Conditions

1. Chapter 9: Understanding the Potential Dangers of Adverse Environmental Conditions

2. Hyperthermia • Hyperthermia = increase in body temperature • Athletic trainers require knowledge and information concerning temperature, humidity and weather to adequately make decisions regarding environmental dangers • Has caused a number of deaths over the years • Must manage heat stress appropriately

3. Hyperthermia (cont’d.) • An individual does not have to be in the south to experience a heat-related illness • Anyone that supervises athletes practicing and competing must realize that heat and humidity impact every geographic region of the United States • Imperative to be able to recognize signs and symptoms associated with heat-related illnesses and to be able to manage them appropriately

4. Heat Stress • Extreme caution should be used when training in the heat (overexposure could result heat stress) • It is preventable • Athletes that train under these extreme conditions are at risk • Physiologically the body will continue to function if body temperature is maintained • Body must dissipate heat to maintain homeostasis

5. Heat Stress (cont’d.) • Heat can be dissipated from the body through 4 mechanisms • Conduction (direct contact) • Convection ( contact with cool air or water mass) • Radiation (heat generated from metabolism) • Evaporation (sweat evaporating from the skin) • Majority of body heat is dissipated through evaporation *** Heat can also be gained via these four mechanisms

6. Heat Stress (cont’d.) • Evaporative Heat Loss • Sweat glands allow water transport to surface • Evaporation of water takes heat with it • When radiant heat and environment temperature are higher than body temperature, loss of heat through evaporation is key • Lose 1 quart of water per hour for up to 2 hours • Air must be relatively water free for evaporation to occur • relative humidity of 65% impairs evaporation • relative humidity of 75% stops evaporation • Heat illness can still occur in cold environment if body is unable to dissipate heat • Caused by dehydration and inability to sweat

7. Monitoring Heat Index • Heat, sunshine and humidity must be monitored closely • Takes into account ambient air temperature and relative humidity • Attempts to determine how hot it feels to the body

8. Heat Index (cont’d.) • WBGT Index incorporates different thermometer readings • Dry bulb (standard mercury temperature) • Wet bulb (thermometer with wet gauze that is swung around in air) • Black bulb (black casing that measures radiant heat) • Formula yields WBGT index • DBT and WBT can be measured with psychrometer(combines both thermometers) • Wet bulb will be lower due to evaporation of water • Drier air = greater depression of wet bulb temperature due to evaporation

10. Heat Illnesses • Heat Syncope • Heat collapse • Associated with rapid fatigue and overexposure, standing in heat for long periods of time • Caused by peripheral vasodilation, or pooling of blood in extremities resulting in dizziness and fainting • Treat by placing athlete in cool environment, consuming fluids and laying down

11. Heat Illnesses (cont’d.) • Exertional Heat Cramps • Painful muscle spasms (calf, abdominal) due to excessive water loss and electrolyte imbalance • Occurs in individuals in good shape that overexert themselves • Treatment • Prevent by consuming extra fluids and maintaining electrolyte balance • Treat with fluid ingestion, light stretching with ice massage • Return to play unlikely due to continued cramping

12. Heat Illnesses (cont’d.) • Exertional Heat Exhaustion • Result of inadequate fluid replacement • Will exhibit signs of profuse sweating, pale skin, mildly elevated temperature, dizziness, hyperventilation and rapid pulse • May develop heat cramps • Core temperature will be ~102o • Critical to obtain accurate core temperature • Performance may decrease • Immediate treatment includes fluid ingestion (intravenous replacement, ultimately), place in cool environment

13. Heat Illnesses (cont’d.) • Exertional Heatstroke • Serious life-threatening condition, with unknown specific cause – body loses ability to dissipate heat through sweating • Characterized by sudden onset - sudden collapse, LOC, flushed hot skin, minimal sweating, shallow breathing, strong rapid pulse, and core temperature of > 104o F • Temperature must be lowered within 45 min. • Drastic measures must be taken to cool athlete • Strip clothing • Immerse the athlete in ice water • Ice bags in the armpits, groin and neck • Transport to hospital immediately

14. Heat Illnesses (cont’d.) • Exertional Hyponatremia • Fluid/electrolyte disorder resulting in abnormally low concentration of sodium in blood • Caused by ingesting too much fluid before, during and after exercise • May be result of too little sodium in diet or in ingested fluids over a period of prolonged exercise • Athletes that ingest large quantities of water over several hours are at risk (marathon, triathlon) • Preventable – must maintain balance • Signs and symptoms – progressively worsening headache, nausea/vomiting, swelling of the extremities • Treatment – medical intervention is necessary

15. Preventing Heat Illness • Must exercise common sense and precaution • Consume fluids and stay cool • Fluid and Electrolyte Replacement • Single most important step taken by a coach to minimize the chance of heat illnesses • Continual re-hydration is critically important • Generally only 50% of fluid is ever replaced and should therefore be replaced before, during and after exercise

16. Prevention (cont’d.) • Fluid replacement should match sweat loss • Most effectively replaced at regular intervals (15 min.) • Time of stomach emptying is critical • Water is absorbed rapidly from intestine • Drink with 6% CHO is eliminated at the same rate if the individual is hydrated • Cold drinks tend to empty rapidly and will not induce cramping or put heart at risk • Drinks with caffeine and alcohol will promote dehydration • Hydration levels can be monitored via urine color and volume • Appropriate hydration = clear urine at normal or above-normal output level 60 minutes following exercise

17. Prevention (cont’d.) • Using Sports Drinks • More effective than just replacing fluids with water • Flavoring results in increased desire to consume • Replaces fluids and electrolytes • Water alone can prematurely stop thirst response and initiate fluid removal by kidneys • Small amounts of sodium help in retention of water • Different drinks have different nutrient levels • Optimal CHO level is 14g per 8 ounces of water • More CHO results in slower absorption • Effective for both short term and endurance activities

18. Prevention (cont’d.) • Gradual Acclimatization • Most effective method of avoiding heat stress • Involves becoming accustomed to heat and exercising in heat • Early pre-season training and graded intensity changes are recommended with progressive exposure over 7-10 day period • 80% of acclimatization can be achieved during first 5-6 days with 2 hour morning and afternoon practice sessions

19. Prevention (cont’d.) • Identifying Susceptible Individuals • Athletes with large muscle mass • Overweight athletes are at an increased risk • Related to proportionality of metabolic heat production to surface area • Athlete with increased fluid loss • While slight differences exist, precautionary measures apply to both males and females • Athletes consuming medications or supplements may have impaired sweating and may predispose them to injury • Athletes with poor fitness levels, a history of heat-related illnesses or anyone with febrile conditions are at increased risk

20. Prevention (cont’d.) • Weight Records • Keep track of before and after measures for first two weeks • If increase in temperature and humidity occurs during the season, weights should again be recorded • A loss of 3-5% = reduced blood volume and could be a health threat • Uniform Selection • Base on temperature and humidity • Dress for the weather and temperature • Avoid rubberized suits • Helmets should be removed whenever possible (for cooling)

21. Hypothermia • Cold weather vs. nature of particular sport • Most activity allows for adequate heat production (increased metabolism) and dissipation, allowing for sufficient functioning • Impact on warm-up and “down time” • Temperature in conjunction with wind chill and dampness or wetness can increase chances of hypothermia

22. Hypothermia (cont’d.) • With muscular fatigue, in cold weather, rate of exercise begins to drop and rate of heat loss relative to heat production may shift • Results in impaired neuromuscular responses and exhaustion • Drop in core stimulates shivering but stops after temp. drops below 85-90oF • Death is imminent when temp falls below 77-85oF.

23. Hypothermia (cont’d.) • Fluid replacement is critical even under colder environmental conditions • Dehydration = decreased blood volume = less fluid available for tissue warming • May be useful to monitor weight of athletes training in cold temperatures • While less common, injury/illness due to the cold still occur, particularly in endurance type activities, winter sports and swimming in cold water

24. Hypothermia (cont’d.) • Frost nip • Involves, ears, nose, chin, fingers, and toes • Occurs with high wind and/or severe cold • Skin appears firm with cold painless areas that may peel and blister (24-72 hours) • Treat with firm pressure, blowing warm air or hands in armpits (if fingers involved) • Do not rub

25. Hypothermia (cont’d.) • Frostbite • Superficial Frostbite involves only skin and subcutaneous tissue • Appears pale, hard, cold and waxy • When re-warming the area will feel numb, then sting and burn • It may blister and be painful for several weeks • Deep Frostbite indicates frozen skin requiring hospitalization • Rapid re-warming is necessary (100-110oF) • During reheating, tissue will become blotchy red, swollen, painful • Tissue may become gangrenous

27. Hypothermia (cont’d.) • Prevention • Apparel geared for weather to provide semitropical microclimate for body and prevent chilling • Waterproof and windproof fabrics that allow passage of heat and sweat and allow movement • Layers and adjusting them are key to maintaining body temperature (during period of (in)activity) • Inadequate clothing, improper warm-up and chill factor can lead to injury, frostbite, and/or minor respiratory problems

28. Overexposure to Sun • Precautions must be taken to protect athletes, coaches, athletic trainers and support staff • Long Term Effects on Skin • Premature aging and skin cancer due to ultraviolet exposure • Premature aging is characterized by dryness, cracking and inelasticity of the skin • Skin cancer is the most common malignant tumor found in humans

29. Sun Exposure (cont’d.) • Using Sunscreen • Can help prevent damaging effects of UV radiation • Sunscreen effectiveness is expressed as SPF (sun protection factor) • Indicates how many times longer an individual can be exposed to the sun with vs. without sunscreen before skin turns red. • Greater the susceptibility the higher the SPF should be used • Should be worn by athletes, coaches and athletic trainers who are outside a considerable amount, and/or have fair complexion, light hair, blue eyes or skin that burns easily

30. Sun Exposure (cont’d.) • Sunscreen use is at its highest March - November but should be used year round (particularly between the hours of 10am-4pm) • It should be applied 15-30 minutes before exposure and re-applied after exposure to water, excess sweating, rubbing skin with clothing or a towel

31. Safety in Lightning and Thunderstorms • #2 cause of death by weather phenomena • NATA has established position statement due to number of athletes and coaches potentially exposed to lightning scenarios • Emergency action plans must be set for this type of event • Involving chain of command, monitoring of weather service, decision making regarding removal and return to field

32. Lightning (cont’d.) • In the event of a storm, shelter indoors should be obtained • Other guidelines • Avoid large trees, flag/light poles, standing water, telephones, pools, showers, and metal objects (bleachers, equipment, umbrellas) • Last resorts find car, ravine, ditch or valley for safety • If hair stands up on hand you are in imminent danger and should get down on the ground but not flat as that increases surface area

33. Lightning (cont’d.) • Additional Guidelines • Lightning is generally accompanied by thunder (except 20-40% of the time due to atmospheric disturbances) • Flash-to-bang methods estimates distance away for the storm • From time lightning is sighted to the clap of thunder count, divide by 5 to calculate the number of mile away • Count of 30 indicates inherent danger • Count of 15 seconds everyone should leave the field

34. Lightning (cont’d.) • NATA and National Weather Service recommend returning to the field 30 minutes following the last clap of thunder or lightning strike • Major misconception is that lightning that is seen striking is coming down • In actuality it is the return stroke of the lightning going back up after it has already hit the ground

35. Lightning (cont’d.) • Lightning Detectors • Hand-held instrument with electronic system to detect presence and distance of lightning/thunderstorm activity (w/in 40 miles) • Can determine level of activity and direction of movement • Provides audible and visual warning signals • Inexpensive alternative to contracting weather services