International Sports Coaches Guide on Heat Management for Athletes

Author: Dr. Mahmoud Radwan – Consultant in Sports Medicine, Al-Hilal Al-Saudi Club

Presented to https://WAFSU.org. This seminar is archived in a course at the site.


A practical guide for coaches, trainers, and medical teams on preventing and managing heat-related conditions in athletes. This presentation explains mechanisms of heat gain and loss, clinical signs of heatstroke, exercise-associated collapse, and hyponatremia, with evidence-based strategies for rapid cooling, hydration, and athlete monitoring. Learn to interpret the Wet Bulb Globe Temperature Index and implement effective prevention protocols to keep athletes safe and performing at their best in high-temperature environments.

heat management, sports medicine, athletic performance, heatstroke prevention, hydration, thermoregulation, exercise physiology, athlete safety, sports injuries, endurance training, coaching education, performance optimization, environmental physiology, heat illness, hyponatremia, athlete recovery, sports science, outdoor training, fluid balance, sports health, training safety, prevention, medical guidelines, heat stress, coaching, elite athletes, physical training, temperature regulation, sports performance, fitness science

1. INTERNATIONAL
SPORTS COACHES
GUIDE ON HEAT
MANAGEMENT FOR
ATHLETES
Dr.Mahmoud Radwan
Consultant in sports medicine
ALHILAL AL SAUDI CLUB

2. EXERCISE IN THE HEAT

3. OVERVIEW
Heat gain and heat loss during exercise
Diagnosis and management of three common
presentations during exercise in the heat:
1. Heatstroke
2. Exercise-associated collapse
3. Heat cramps
D.D. of Heatstroke-Hyponatremia
Guidelines for the prevention of heat illness

4. EXERCISE IN THE HEAT


.Sports Med clinicians must be well versed in both
prevention and management of heat-associated
illness.
.Humans can only survive core temperature >41 for
short periods
.proteins denature at a body temperature of 45
.Humans have developed an almost unmatched
capacity to sweat and to lose heat during exercise
,hence we are able to regulate our body
temperatures even during exercise of long
duration in environmental conditions that would
otherwise be considered extreme.

5. EXERCISE IN THE HEAT
Heat injury,in particular heatstroke,occurs to
persons exercising in much less severe
environmental conditions when the total heat
load cann,t explain why heatstroke developed.
This suggests that individual susceptibility plays
a much more important role in the development
of heatstroke in contrast to environmental
conditions

6. MECHANISM OF HEAT GAIN AND
LOSS
Heat production:
Heat during exercise is produced by both
endogenous and exogenous sources
Endogenous sources are muscle activity and
metabolism
Exogenous sources are : heat transfer to the body
when environmental temperature exceeds the
body temperature
The rate of heat production and the risk of heat
stroke should be greatest in those who run the
fastest and have the highest work rate

7. HEAT LOSS
It occurs by conduction,convection,radiation,or
evaporation
During rest thermal balance is maintained by
convection of heat to the skin surface and
radiation of heat to the environment
During exercise,more heat is produced and
sweating provides compensatory heat loss
through evaporation
When the environmental temperature equals or
exceeds body temperature,sweating is the
predominant mechanism of heat loss

8. HEAT LOSS
Sportspeople exercising in these conditions rely
almost exclusively on evaporative heat loss to
regulate body temp.(Braker Clin Sp Med 2001)
The humidity significantly affects the sweating
mechanism to cool down the body
The combination of high temp. and high humidity
is particularly dangerous as both will result in a
substantial increase in body core temp. even in
relatively short-distance races(6-15 km)
The effects of both humidity,solar and ground
radiation,air temperature and wind speed are all
included in the wet bulb globe temp.index

9. THE WET BULB GLOBE TEMP.
INDEX
WBGT index is a comprehensive heat index used to
measure the potential heat stress on human body
by combining air temperature, humidity ,wind
speed and solar radiation .
WBGT is used to prevent heat-related illnesses in
outdoor activities and training.
Endurance events with high intensities of exercise
should not be held when the WBGT index exceeds
28 c
Intermittent activities with less heat production
can be played at higher temperatures provided
adequate rest intervals are allowed between bouts
of activity

10. CLINICAL PERSPECTIVE
Appropriate clinical assessment of the athlete
who presents after exercising in the heat is the
cornerstone of good management
The initial assessment is based on the athlete
level of consciousness and knowledge of where in
the race the sportsperson collapsed
Athletes who are seriously ill show alterations in
their level of consciousness and almost always
collapse before completion of the race
Measuring rectal temp,BP,HR and the blood
sodium conc.provide additional diagnostic
informations

11. CLINICAL PERSPECTIVE
Clinical ex.cann,t determine accurately the level
of dehydration
Measurement of the body wt. loss provides some
measure of the likely fluid loss during prolonged
exercise like marathon running
In longer races >25km when hpoglycemia is more
likely, a glucometer should also be used
In mass events >4hrs,equipments for measuring
serum sod.conentration must be avilable so that
potentially lethal exercise-induced hyponatremia
can be diagnosed faster and efficiently
IV therapy if sod.level is <135 or>148mmol/L

12. PRACTICE PEARL
Whether or not the sportsperson is conscious or
unconscious is the most important sign guiding
the differential diagnosis
Braker Clin Sp Med 2008

13. CAUSES OF UNCONSCIOUSNESS IN
ATHLETES
Medical conditions (not related to exercise):
Cardiac arrest
Grand mal epilepsy
Subarachnoid haemorrhage
Diabetic coma
Exercise –related disorders are:
Heatstroke
Hyponatremia
Severe hypoglycemia which is an uncommon
cause of exercise-related come in non-diabetics

14. ALERT SIGNS IN UNCONSCIOUS
ATHLETE
1.Rectal temperature>41c
2.Heart rate>100 beats/min
3.Systolic blood pressure<100mmhg
If rectal temp is above 41c the diagnosis is
heatstroke
If rectal temp is below 40c in an unconscious
patient , the BP and HR are not grossly abnormal
and there is no other obvious medical
conditions ,the probability is that the sportsperson
has exercise-associated hyponatremia (EAH) or
hypochloremia(rare) which is an electrolyte
abnormality causing cerebral edema

15. GUIDELINES FOR DETERMINING THE
SEVERITY OF THE COLLAPSED
SPORTSPERSON,S CONDITION
Non-severe Severe
immediate assessment
conscious unconscious or altered mental
state
alert confused,disorinted,aggressive
rectal temp<40 c rectal temp >40 c
systolic BP>100mmhg systolic BP<100mmhg
HR <100 beats/min HR>100/min
Specialized assessment
bl.gluc. level 70-180mg/dl Bl.gluc.level <70
or>148mmol/dL
serum sod conc.135-148mmol/L serum sod conc.<135
or>148mmol
body wt. loss 0-5% body wt. loss >10%
body wt.gain >2%

16. 1.HEATSTROKE( TEMP.ABOVE 41C)
The highest rectal temp. are usually seen in the
fastest runners competing in events of 8-21 km
Symptoms that are usually associated with
higher rectal temperatures include:
Dizziness,weakness,nausea & headache
Confusion and disorientation
Irrational behavior including aggressive
combativeness or drowsiness progressing to coma
Examination:
Hypotension
Tachycardia

17. HEATSTROKE

18. HEATSTROKE
The presence or absence of sweating does not influence the
diagnosis
Recovery of CV function occurs with normalization of the
cardiac output and with an increase in peripheral vascular
resistance
If,during exercise,a previously healthy sportsperson shows
marked changes in mental functioning (collapse with
unconsciousness) or a reduced level of consciousness
(stupor,coma) ,or even mental stimulation in the form of
(irritability,confusion) any/ or all of which in association
with a rectal temp. above 41c, the diagnosis of heatstroke
is confirmed and warrants immediate initiation of cooling

19. MANAGEMENT OF HEATSTROKE
Rapid reduction of rectal temperature to 38c will result in
better prognosis
Place the patient in a bath of ice water for5-10 min
Care must be taken to avoid inducing hypothermia
Shivering indicates that core temp. has decreased to 37c or
even below
IV fluids may be given to correct the expected dehydration
and to assist in stabilizing the hyperkinetic circulation
Rapid 1-1.5 L 0f 0.5% or 0.9% saline can be given initially
However, cardiac function is compromised in hyperthermia
and aggressive fluid therapy can induce pulmonary edema
Mortality from heatstroke should be zero in healthy athlete
who are cooled promptly

20. MANAGEMENT OF HEATSTROKE
Indeed,it is usual for sportspeople to be fully recovered and
ambulatory within 30-60 min. of collapse,providing they
are correctly and efficiently treated and they don,t have a
predisposing medical condition that explains their
increased individual susceptibility to heatstroke a clinical
case known as Exercise-induced malignant hyperthermia
Any delay in cooling therapy can convert an
uncomplicated case of heatstroke into a potentially fatal
condition
However very rare cases of heatstroke follow a malignant
course with a fatal outcome occuring within a few hours
despite appropriate medical care

21. COMPLICATIONS OF HEATSTROKE
CV:
Arrythmia
Myocardial infarction
Pulmonary edema
Neurological:
Coma,confusion & stroke
GIT:
Liver damage and gastric bleeding
Muscular : rabdomyolysis
Haematological:
Disseminated intravascular coagulation
Renal failure

22. IS HOSPITAL ADMISSION
INDICATED?
For follow up and close observation
Failure to regain consciousness within 30 min. after proper
treatment that returns rectal temperature to 38c
Failure to achieve cardiovascular stability during this time is an
absolute indication for hospital admission
A persisting tachycardia and hypotension in the supine head-
down position suggests that cardiogenic shock is developing
Is the hyperthermia the cause of the condition or merely a sign of
another potentially more serious condition?

23. IS URGENT INTENSIVE CARE
INDICATED?
Rhabdomyolysis: severe cases of muscle damage and break down with
evidence of disseminated intravascular coagulation, this condition
requires urgent intensive care treatment .
Classic triad of Rhabdomyolsis are :
1. Severe muscle pain
2. Muscle weakness
3. Dark or tea-colored urine
Confirmation of diagnosis via blood test to measure creatine kinase
(CK) which is a marker for muscle damage.
TTT by IV fluids , electrolytes correction and medication adjustment .

24. 2.EXERCISE-ASSOCIATED COLIAPSE
Collapse that occurs in sportspeople who successfully complete
endurance events without distress but suddenly afterwards
develop symptoms and signs of postural hypotension when they
stop exercising .
In such cases if the rectal temperature is elevated and the patient
has an altered level of consciousness , heatstroke is the correct
diagnosis
There may be abnormal perfusion of the splanchnic
circulation ,with loss of a large fluid volume into the highly
complaint splanchnic veins
Dehydration can not be an incriminated factor in collapse
The diagnosis of exercise-associated collapse/EAPH can be made
on the basis of a typical history .
Findings of a PH reversed by lying supine with pelvis and legs
elevated and exclusion of readily identifiable medical syndromes
such as diabetes and heatstroke

25. MANAGEMENT OF EA-COLLAPSE/
PH
Exercise-associated postural hypotension (EAPH) patients if
are conscious , so encourage them to ingest fluids orally
during recovery
Sports drinks containing both glucose and electrolytes are
appropriate , provided the sportsperson does not have
evidence of fluid overload .
Managing the patient in head-down position with pelvis and
legs elevated is always dramatically effective and producing
a more stable CV system within 30-90 seconds usually with
instant reversal of symptoms
Most sports people wit EA collapse are able to stand and
walk unaided within 10-30 min of appropriate treatment
IV fluids should be introduced only if sports people show
signs of dehydration(dry mouth , loss of skin turgor , sunken
eyeballs and inability to spit).

26. MANAGEMENT OF EA-COLLAPSE/PH
Continuation of IV therapy, only if, the patient is managed
in Trendelenburg position with heart rate>100.min and
still hypotensive
In such cases the possibility of an underlying cardiac
condition causing a reduced cardiac output must be
considered and properly treated .

27. 3.HEAT CRAMPS
Cramps can occur at rest, during or after exercise
undertaken in any environmental conditions
The popular belief that cramps are caused by severe
dehydration and large sodium chloride loss that develop
during hot conditions has no scientific basis
They are specific neither to exercise , nor to exercise in the
heat
The most recent hypothesis proposes that cramps probably
result from alterations in spinal neural reflex activity
activated by fatigue in susceptible individuals .
Fatigue increase excitatory signals to motor nerves causing
contraction and inhibit relaxation .
The term “heat cramps” should be abandoned as it clouds
understanding of possible neural nature of this condition .

28. MANAGEMENT OF CRAMPS
Muscle stretching is very effective
Application of ice and massage of the affected muscle may also
help
Oral fluids if signs of dehydration are evident
IV normal saline and IV magnesium therapy have been used
in Triathlon , however, clinical trials of either treatment have
yet to be published .
More recently , evidence has accumulated that the ingestion of
pickle juice may speed up recovery from cramps by a central
neural mechanism faster than water .
Pickle juice contains acetic acid which send signals to Spinal
Cord to calm overactive nerves , rather than by replenishing
electrolytes .
Just sip a small amount slowly followed by water because of
its high sodium content .

29. FLUID OVERLOAD HYPONATREMIA
Hyponatremia is perhabs the most important D.D. in athletes
who seek medical attention at an endurance event undertaken
in the heat lasting four or more hours
Any sportsperson who becomes unconscious during or after
ultra-distance running or triathlon races and whose rectal
temperature is not elevated should be considered to have
symptomatic hyponatremia(EAHE) until measurement of the
serum sodium concentration refutes the diagnosis
Sportspeople with EAHE and serum sodium concentration below
129mmol/L are overhydrated by between 2-6L and the physician
should be aware of this diagnosis in a patient with an altered
level of conscious
If the patient is conscioucs,he may complain of feeling bloated
or swollen,accordingly race identification bracelets feel and are
noticeably tighter
Vomiting of clear fluid is another indicator of overhydration

30. MANAGEMENT OF EAH & EAHE
The current management includes:
* Bladder catheterization to monitor the rate of urine
production during recovery.
Spontaneous recovery will occur if urine>500mi/hr.
*No fluids by mouth.Salt tablets&sodium containing foods can
be given
*High sodium(3-5%) solution given IV provided they are
infused slowly(50-100ml/hr.)
*Use of diuretics may be justified to initiate duresis
N.B.* providing hypotonic or isotonic fluid to patients who are
unconscious because of cerebral edema delays recovery and may
produce a fatal result
* The avoidance of over-drinking is the sole factor required to
prevent exercise-associated hyponatremia

31. SPORTS DRINKS IN HYPONATREMIA
* Sports drinks plays no role in prevention of EAH
-Sports drinks are markedly hypotonic and their ingestion
adds substantially more water than sodium to the body
-EAH is always also due to excessive secretion of ADH with
resultant water retention and sodium diuresis , thus , the
ingestion of any fluid regardless its sodium content will
cause further fluid retention with excretion of all sodium
present in the ingested fluid
-A recent study funded by the sports drink industry confirmed
that sodium ingestion during exercise
produced no significant effect
Noakes TD Med Sci Sp 1991
- However , this study and other researches still debatable .

32. GUIDELINES FOR THE PREVENTION OF
HEAT ILLNESS
Perform adequate conditioning
Acclimatization if competing in unaccustomed heat or
humidity
Avoid adverse conditions
Alter training times
Wear appropriate clothing
Drink an appropriate amounts of fluids before the event
Sportspeople can be assured that they need to drink only
according to the dictates of their thirst*Goulet
SpMed2011*
Ensure sportspeople and officials are well educated
Provide proficient medical support

33. HERE COMES THE CHAMPION

34. THANK YOU