EXTREME HEAT GUIDELINES August 2008

Transcription

1 EXTREME HEAT GUIDELINES August 2008 Cricket Victoria ( CV ) has formulated these extreme heat guidelines ( Guidelines ) to minimise the risk of injury, illness and possible death in Victorian Cricket Pathway and associated programs conducted by its Game Development department, by assisting administrators, officials, coaches and participants to recognize and manage potentially dangerous situations. The first part of these Guidelines provide background information including suggested strategies to minimise the risk of extreme heat effecting players and officials. CV has provided the information in these Guidelines as indications of best practice only. These Guidelines are not a substitute for professional advice from a health practitioner. Each individual participant or official will react differently to heat and therefore each individual must be aware of their own capabilities. CV warns participants that participating in physical activity in extreme heat is inherently dangerous and may cause injury or illness to participants. Participants take part at their own risk. The second part of the Guidelines sets out CV s policy and playing conditions that will be followed in the CV s Pathway and other development programs ( Policy ). This Policy must be adhered to at all times. Background There is scientific evidence which indicates that undertaking moderate to high intensity exercise in extreme heat is dangerous. The scientific evidence uses Wet Bulb Globe Temperature ( WBGT ) as the best measure of heat strain currently available. Please note that WBGT is not the same as air temperature; it accounts for the levels of humidity, radiation, wind movement and air temperature. Measuring WBGT is done using a Wet Bulb Globe Thermometer. These devices are not readily available and are costly. Ambient temperature information on the other hand is readily available from the Bureau of Meteorology ( BOM ) website as is the measure for relative humidity. If this is combined with the raw calculations of WBGT from the BOM website it is possible to calculate when injury and illness through heat indicators are at a medium to high level. Between 23 & 28 degrees celsius (using the WBGT calculation) there is a high risk of heat injury, between 18 & 22 degrees celsius a moderate level of heat injury and below 18 degrees celsius a minimal risk of heat injury. NB. With no regulating mechanisms in place we can ascertain that

2 some competitors may be at risk when the WBGT measurement is above 18 degrees Celsius. During competition, a competitor may produce 15 to 20 times the heat they produce when at rest. Dissipation of this excess heat is primarily achieved through sweating. If the body s ability to dissipate heat is compromised, core temperature in an average size individual may rise one degree Celsius for every five minutes of exercise if no temperature regulating mechanisms are activated. Some factors that impair the body s ability to dissipate heat are: 1. high ambient temperature; 2. solar radiation; 3. humidity (this compromises the efficacy of sweating); and 4. dehydration. Timing of games Where possible, games or sporting activities that are conducted on days where calculations suggest the WBGT is likely to exceed 29 degrees celsius, then activities should commence early in the morning. Note, a WBGT reading of 29 degrees celsius is approximately 36 degrees celsius in ambient temperature calculations. However, there is not a precise formula to calculate this because factors such as wind strength, cloud cover and humidity are all taken into consideration. Hydration The more an athlete sweats, the more fluid he/she must consume to avoid dehydration. High levels of dehydration may increase the risk of heat stress. To diminish the risk of heat stress fluid should be consumed before, during and after activity. It is recommended participants drink at least 7-8ml of fluid per kg of body mass no more than 2 hours before exercising to promote adequate hydration and allow time for excretion of excess water. During exercise it is recommended that participants should drink fluid at regular intervals to replace water lost through sweating. Participants should aim to drink at least 3ml per kg of body mass (about 250ml for the average athlete of around 70 kilograms every 15 to 20 minutes). However this may vary dependent on the intensity of the exercise and the rate of sweating. NB. Fluid taken should be cooler than the ambient temperature. Water is considered an adequate fluid option for activities lasting up to one hour although there is evidence that sports drinks such as Gatorade do provide a benefit for exercise that is less than one hour in duration. Participants in events or activities exceeding one hour are recommended to use carbohydrate based sports drinks

3 such as Gatorade as a means of replacing fluids, carbohydrates and electrolytes lost during prolonged activity. In high risk conditions players should be encouraged to drink fluids at scheduled drinks breaks and should be provided convenient access to fluids during activity without unnecessary interruption to the game or event. Officials and event organisers should also consider including additional drinks breaks for players in conditions of high risk. In regard to post -event rehydration, it needs to be remembered that this can take 24 hours or more. Player Rest and Rotation In conditions of high risk, participants should be provided opportunities to rest through the use of player interchange or substitution. The period of rest should be determined by the WBGT at the time of the event or activity. For WBGT temperatures greater than 21 degrees celsius and less than 25 degrees celsius (approximate ambient temperature equivalent of 26 to 30 degrees celsius) all players should be rested for at least 10% of the period they would normally participate. i.e. if the activity normally runs for 60 minutes the rest period for the player should comprise at least 6 minutes during the period. For situations where the WBGT is greater than 26 degrees celsius and less than 29 degree celsius (approximate ambient temperature equivalent of 31 to 35 degrees celsius), all players should be rested for at least 25% of the period they would normally participate. This may be achieved by rotation of players through an interchange procedure or via the reduction in the regular playing time for all players. The positive effects of rest breaks should also be maximised by employing the strategies such as: allowing players to rest in naturally shaded areas, or providing portable structures that create shade where and when required; providing fans, ice packs or allowing players to take showers; providing additional fluids to allow participants to spray or douse themselves to assist cooling. REDUCING THE RISK OF HEAT ILLNESS (Children) 1. Shade and Drinks Organisers of activities that are conducted under hot conditions must provide sufficient shade, and regular drinking opportunities. This is particularly critical where the fitness and state of acclimatization of the young participants are uncertain.

4 It is recommended that water or sports drinks such as Gatorade are provided whenever children are being active. More fluid, however, appears to be consumed by young people when the drinks offered are perceived as palatable to them. Therefore, for children and adolescents having trouble drinking adequate tap water, flavoured drinks such as commercially available sports drinks may need to be considered. However, the high energy content of some flavoured drinks may be unnecessary during exercise where athletes are operating at lower intensity or if they have a genuine (rather than an aesthetic) need to lower body fat levels. It is recommended that young athletes begin regular drinking routines using water or sports drinks such as Gatorade during training and competition. Regular and effective drinking practices should become habitual to young athletes before, during and after activity. Individuals should monitor weight changes before and after workouts and know the amount of fluid that they are likely to require. The electrolyte content of some sports drinks consumed following activity may shorten the time taken to recover, particularly in well-trained young athletes who sweat considerably more than their sedentary peers. 2. Acclimatisation and Overweight Children In addition to the risks associated with activity in the heat for unfit and unacclimatised young people, coaches/supervisors of overweight children and adolescents should take extra precautions to lessen the potential for heat gain. We recommended that whenever activity in hot conditions is unavoidable with these children, coaches/supervisors decrease the volume and duration of physical activity, and increase opportunities for drinking, rest, and shade as a matter of priority. At the onset of hot weather, younger athletes may take longer to acclimatize. It is therefore recommended that training volumes (duration and intensity) decrease during the first few weeks of hot weather. Increased times for rest, using access to shade more frequently, and increasing the number of mandatory drinking breaks are recommended for the young athlete when the weather becomes noticeably hotter. 3. Clothing Clothing should be, loose fitting, of natural fibres or composite fabrics, with high wicking (absorption) properties, that provide for adequate ventilation are recommended as the most appropriate clothing in the heat. This clothing should further complement the existing practices in that protect the skin against permanent damage from the sun. In addition to these recommendations made for the general population, it is recommended that summer based cricket select uniforms that minimize heat gain and that coaches, teachers, and parents encourage children and adolescents to wear appropriate clothing in layers that can be easily removed during activity.

5 4. Heat Illness Register To improve the understanding of children and adolescents activity in the heat, it is recommended that a register of heat-related illness be established. This may comprise a system within which all aspects of heat related illness incidents are recorded. Items of note may include the individual afflicted and their symptoms, the time of the incident, the environmental conditions, the physical activity undertaken, the immediate treatment and subsequent action taken. The system is recommended to aid in the identification of individuals that have previously experienced some form of heat illness and therefore may require additional attention to ensure prevention strategies are adopted by these individuals. Symptoms of heat illness may include (but are not limited to): light headedness or dizziness; nausea; obvious fatigue; cessation of sweating; obvious loss of skill and coordination/clumsiness or unsteadiness; confusion; aggressive or irrational behaviour; altered consciousness; collapse; or ashen grey pale skin. Serious heat illness in sport presents as heat exhaustion or heat stroke. Heat exhaustion is the more common sports-related heat illness. Heat stroke is rare, but it is a life threatening condition. Heat exhaustion. Participants who collapse after exercise, are likely suffering heat exhaustion with low blood pressure (postural hypotension), but some may have heat stroke. Heat stroke. Those who show signs of altered mental function, loss of consciousness or collapse during exercise are likely suffering heat stroke. Sports participants showing signs of: confusion; loss of skill; loss of coordination; or irrational behavior, should be stopped and removed from the field immediately. If a sports participant is exhibiting signs of heat illness you should seek first aid or other medical attention for the participant. In addition, take the following action:

6 remove the person from the field; lay the person down in a cool place; raise legs and pelvis to improve blood pressure; remove excess clothing; cool by wetting skin liberally and vigorous fanning (evaporative cooling); apply ice packs to groin, armpits and neck; give cool water if conscious. Persons suffering from heat exhaustion usually recover rapidly with this assistance. If the athlete remains seriously ill, confused, vomiting or shows signs of altered consciousness call ambulance immediately and seek further medical help.

7 EXTREME HEAT POLICY This second part of CV s Extreme Heat Guidelines sets out CV s policy and the playing conditions that will be followed in the CV s Pathway and other development programs. This Policy is in place so that all athletes, umpires and other field officials have a safe environment to work in. The Policy must be strictly adhered to at all times. The Policy applies to: all Pathway Championship games; Pathway training sessions and practice games; all practice sessions and games under the control of the Game Development department; other events as determined by CV from time to time. It is rare for more than two games to be played in one location with some competitions spread across the wider metropolitan Melbourne area i.e. Frankston to Geelong, with some Championships in rural areas. This Policy will assist conveners with decisions relating to extreme heat. All staff and management groups (coaches, team managers, scorers, support staff) must be aware of this Policy and must consider the following issues: 1. Training & playing advice for extreme heat conditions; 2. Hydration & Re-hydration; 3. Modification of warm ups; 4. Rest periods; 5. Shade requirements; 6. Clothing (including hats, long sleeve shirts, sunglasses); 7. Sunscreen; 8. Scheduling of games; 9. Game day contacts re temperature advice; 10. First aid kit must be available at all times; 11. First aid qualified staff member at each game where possible; 12. Symptoms associated with heat illness; and 13. Person in charge should have the location and number of local emergency outlet, or if in doubt should call 000 for an Ambulance. An Extreme Heat Day means a day where the air temperature forecast is for 30 degrees celsius or greater in a given location. Training Sessions All training sessions scheduled for Extreme Heat Days should be: Either early morning or late afternoon but, generally, out of the hottest part of the day (between 11.00am and 3.00pm). Indoors or in the shade where possible.

8 Practice Games These should be scheduled, where possible, to commence before 10.00am with conditions monitored throughout the day in line with these guidelines. Refer to point 3 under Championship & Carnival Games below for more information. Championship & Carnival Games 1. All Under 18 & U16 games to commence at 10.00am. (50 over per side format) 2. All Under 14 games to commence at 10.30am. (40 over per side format) 3. The Cricket Victoria Convener can inform regions, umpires and Clubs of an earlier start time if the forecasted temperature is for an extreme heat day. This would be done with at least 12 hours notice. If both regions agree games can start earlier than the designated time and this can be decided on the morning of the match. 4. All games shall be played under normal conditions except in the following situations involving extreme heat: At 12.00pm on any scheduled Championship event day, the Championship convener will forward via text message to match day managers and team management staff the current temperature and a relevant extreme heat warning (where applicable). In formulating the extreme heat warning (where applicable), the Championship convener will review information on the BOM website relevant to each game/s location. CV will follow the Sports Medicine guidelines for extreme heat ( which state that temperature and participant safety levels should be monitored where the Air Temperature reaches 35 degrees celsius and above. When the Air Temperature surpasses 35 degrees celsius at, or around, a particular location, the Championship convener will immediately notify the CV match day manager at that location, who will in turn notify the umpires and team management. After information has been obtained regarding Temperature levels and advice given that extreme heat levels have now been attained, the umpires, in conjunction with the relevant CV match day manager, will determine if conditions are sufficiently safe for play to continue in its normal course. These officials can make this determination in their absolute discretion. If the umpires and relevant CV match day manager determine that conditions are unsafe for play to continue in its normal course, they shall be able to take such steps as they deem necessary in their absolute discretion to mitigate the risk to participants. These steps may include: i. increasing the length of breaks between innings or overs; ii. increasing the number of drinks breaks; or iii. stopping play such period of time until it is determined that conditions are safe for play.

9 In taking these steps, the umpires and relevant CV match day manager shall, wherever possible, continue to seek that matches be completed. In matches that are affected by these extreme heat provisions, the match shall be concluded as soon as a result is reached. Note that in practice match or training situations where a CV match day manager and/or umpires may not be present, decisions on all extreme heat playing conditions should be made by the person in charge. On match days, the Temperature levels will continue to be monitored by the Championship convenor every 30 minutes from 12.00pm. In the event that CV match day managers and information on the BOM website relevant to each match location indicates that play is unsuitable at more than 60% of all locations where games are being played in championships, then the championship convener will have the right to forego championship points for that day s play. Note that temperatures will only be centrally monitored on Championships/Carnival event days. For information about extreme heat for all other cricket activities (including practice matches and training outside of championship events), call the CV Game Development department on (03) during business hours of 9.00am to 5.15pm EST weekdays for information off the BOM website. If the activity is held on a weekend or public holiday then the person in charge (if they have no access to the BOM website) should call for Melbourne Metropolitan temperature updates or for all Country information. References The following sites will be used to ascertain temperature levels: Conversion tables (Apparent Temperature & Wet Bulb Globe Temperature) Latest Weather Observations for Melbourne Area Latest Weather Observations for Victoria (Other) Championship & Practice Matches The following will apply in all games played on Extreme Heat Days. Each team to have their own 25 litre drink container with tap for dispersing. NB. No dipping of cups into the container under any circumstances. All players to have their own drink bottle and or cup. One Esky style container to be placed at fine leg/3 rd man area at each end of the ground containing bottles of water for fielding team members. Bowlers to be rotated off the field after each spell to re-hydrate, cool down in the shade or shower.

10 Fielders must be rotated at least once in any 60 minute period during the game. Umpires and team mangers to agree on the amount of drink breaks in each innings, erring on the side of more than less, and applicable to the conditions. Where there is no natural shade, a shade structure must be supplied. Any heat illness issue will be reported on an official injury report form and placed on the heat illness register.

11 Page 11