Environmental Conditions Related to Physically Active Individuals

1. Environmental Conditions Related to Physically Active Individuals

2. Illnesses & Injuries from Environmental Concerns Heat-related Heat Rash, Heat Syncope, Heat Cramps, Heat Exhaustion, Heat Stroke, Acute Exertional Rhabdomyolysis, Exertional Hyponatremia Cold-related Frost Nip, Frostbite Lightning Altitude Acute Mountain Sickness, Pulmonary Edema, Sickle-Cell Trait Reaction Air Pollution Sun-related Circadian Dysrhythmia

3. Hyperthermia: Extreme heat Predisposing factors: Individuals poorly acclimatized or conditioned Inexperienced with heat injuries Large muscle mass Clothing Oil-based or gel-based sunscreens Obese Those who have lost 2% or more of body weight during practice (mild dehydration � impairs cardiovascular & thermoregulatory response) 3-5% weight loss reduces blood volume & can lead to health threat

4. Preventing Heat Illnesses Hydration Fluid & Electrolyte replacement Acclimatization Identify susceptible individuals Clothing Maintain weight records** Monitor temperature & humidity readings

5. Heat Related Injuries Heat Rash � red, raised rash with prickling & tingling sensations during sweating Heat Syncope � heat collapse, fainting, dizziness Heat Cramps � imbalance or loss of water, electrolytes (sodium, potassium, magnesium, calcium) Heat Exhaustion � inadequate replacement of fluids lost through sweating; hypothalamus functioning normally Heat Stroke � breakdown of the thermoregulatory mechanism - can�t sweat to cool body down Acute Exertional Rhabdomyolysis � sudden skeletal muscle breakdown, Renal destruction (rhabdomy/o = skeletal muscle; lysis = destruction, breakdown) Exertional Hyponatremia � fluid/electrolyte disorder; low concentration of sodium in the blood (hypo = low; natr = sodium, emia = blood)

6. Body Temperature *Core temperature � regulated by the hypothalamus Cooling mechanisms or heating mechanisms in the body take place to regulate this Internal Sources of Heat: (heat gain) Basal Metabolism � caloric expenditure while a person is at rest (minimum amount of energy required to maintain life at normal body temperature Exercise Metabolism � heat from exercise

7. Cooling Mechanisms of the Body (heat loss) Conduction � transfer of heat from body to surrounding environment (physical contact with other objects) Example: Turf Convection � depends on movement of molecules in contact with the body surface Example: Cool breeze Evaporation � occurs between the skin & environment, and respiratory tract & outside environment Major method of dissipating core temperature; air humidity has a factor in this Radiation � exchange of heat energy by electromagnetic waves Example: Sun

8. Monitoring Environmental Heat DEW POINT - Temperature to which air must be cooled at a constant pressure to become saturated HEAT INDEX - Combination of air temperature & humidity that gives a description of how the temperature feels NOT the actual air temp HUMIDITY - Amount of water vapor in the air Often confused with relative humidity or dew point Related terms: absolute humidity, relative humidity, & specific humidity

9. Wet Bulb Globe Temperature Index - developed by the U.S. military to model the stress imposed on humans by hot humid environments WBGT Index � weighted sum of three component temps: Globe temperature (GT) - measured by a thermometer inside a black sphere passively exposed to the ambient environment. Temp. provides an indication of the mean radiant temperature of the environment & accounts for 20% Wet bulb temperature (WBT) - uses a wet wick wrapped around a thermometer & swung around in the air Temp. indicates the amount of cooling provided to the human subject through evaporation & accounts for 70% Dry bulb temperature (DBT)- measured by a standard air thermometer. Temp. is the temperature of the ambient air & accounts for 10% WET BULB GLOBE TEMPERATURE INDEX � WBGT � 0.1 x DBT + 0.7 x WBT + GT x 0.2

10. Wet Bulb Globe Index (WBGT) meter Sling Psychrometer Digital Psychrometer http://www.ambientweather.com/dips.htm http://www.weather.com

12. Hypothermia: Extreme Cold Predisposing factors: Inadequate insulation Restrictive clothing Alcohol/tobacco use Decreased circulation Three weather-related factors: Low temperatures Wind chill Dampness in the air Prevention: Clothing Monitor weather Warm-up Hydration

13. Cold-RelatedInjuries Frostbite � Frostnip � freezes skin tissue on ends of toes, fingers, nose Superficial � freezes skin & underlying tissue Deep � freezes subcutaneous layers General body cooling Mild shutdown � 90�-94� Severe shutdown � below 90�

14. Lightning Safety Observe basic first aid procedures to manage victims of lightning strike. Survey the scene Activate EMS Move the victim carefully to safe location Evaluate & treat for apnea, asystole, hypothermia, shock, fractures & burns Flash-to-Bang Theory Flash Count time Bang � stop Divide number by 5 (distance in miles)

15. Recommendations for Lightning Safety Formalize & implement a comprehensive, proactive lightning safety policy or EAP Seek safe location @ 1st sign of lightning or thunder activity. If count is 30 seconds or less, you should already be inside or should be looking for a safe location. Once activities have been suspended, wait at least 30 minutes after last sound of thunder or lightning flash before resuming.

16. If outside: Avoid contact with, or be in proximity to, the highest point of an open field or open water Avoid taking showers & using plumbing facilities & using land-line telephones during activity. If you feel your hair stand on end or skin tingle or hear crackling noises, assume the lightning-safe position Crouched on ground Weight on balls of feet Feet together Head lowered Ears covered DO NOT LIE FLAT ON THE GROUND!

17. Altitude Maximum O2 uptake decreases as altitude increases Increased altitude Reduction in barometric pressure & partial pressure of O2 in inspired air is low Results in hyperventilation (not enough O2 getting to the tissues) Natives of high altitudes have: larger chest capacity, more alveoli, more capillaries to transport blood & higher RBC level

18. Altitude Illnesses Acute Mountain Sickness � change from low to moderate elevation S&S: Headache, nausea/vomiting, sleep disturbance, dyspnea Attributed to sodium/potassium balance in brain (fluid retention) Pulmonary Edema � change to high altitude (over 9,000 ft) Lungs may accumulate some fluid S&S: Cough, headache, weakness, dyspnea Sickle-Cell Trait � abnormal RBC shape Found in 8-10% of African Americans When abnormal RBC become deoxygenated as a result of exercise at high altitudes, the cells tend to clump together

19. Air Pollution Smog � carbon monoxide & sulphur dioxide Sulfur Dioxide S&S: increased resistance for air movement in & out of lungs, increased susceptibility to lung diseases, adverse effects on asthmatics Carbon Monoxide S&S: (reduces hemoglobin�s ability to transport O2) psychomotor, behavioral, & attention-related activity interference Photochemical haze � nitrogen dioxide & stagnant air with sunlight produces ozone Ozone S&S: shortness of breath, pain with deep breathing, chest tightness, coughing, nausea, eye irritation, fatigue, lung infections/irritations Prevention � exercise at times when reduced air pollution occurs

20. Sun-Related Injuries Overexposure to the Sun Effects to the skin Prevention Use Sunscreens with high SPF

21. Circadian Dysrhythmia Jet lag Circadian = about 24 hours Body�s cyclical mechanism � release of hormones, body temperature, S&S: fatigue, mental effects, headache, changes in BP, heart rate, hormonal release Prevention: Hydration, eating habits, (p. 181)