The tragic death of Manly rugby league player Keith Titmuss in 2020 due to exertional heat stroke is a reminder of the life-threatening nature of the condition.
Authors
Samuel Chalmers
Senior Lecturer in Human Movement, University of South Australia
Orlando Laitano
Assistant Professor, University of Florida
Titmuss died after a pre-season training session which was “more likely than not inappropriate”, according to the magistrate who oversaw a recent inquest.
Deputy NSW coroner Derek Lee made several recommendations in reviewing Titmuss’ death in the hope of reducing the chance of it happening again.
So, what is exertional heat stroke, and what should athletes and coaches know about it?
What is exertional heat stroke?
Exertional heat stroke is the most severe form of a spectrum of conditions classified as exertional heat illness.
During sport and exercise, the body is challenged to maintain an ideal core temperature of about 36-38°C.
This is because exercise produces a massive amount of internal heat, which needs to be released from the body to avoid overheating. Hot and humid conditions stress the ability of an person to release this internal heat, as well as potentially adding to the heat load.
If someone’s body is unable to control the rise in core temperature during physical activity, it may ultimately display central nervous system dysfunction. Signs of this include loss of muscle control in the arms and legs, combativeness, seizures, or loss of consciousness.
A highly elevated core temperature (typically, but not always, above 40°C) and multi-organ damage and failure are also characteristics of exertional heat stroke.
In one study, 27% of people suffering severe exertional heat illness died. But even those who survive often face long-term negative health consequences, such as an increased risk of cardiovascular disease later in life.
How often does exertional heat stroke occur?
Less severe forms of exertional heat illness (termed as heat exhaustion and heat injury) are more common during sport and exercise than exertional heat stroke. However, the life-threatening nature of the condition means precautions must be considered, especially for summer sports.
The condition strikes “weekend warriors” through to elite athletes and military personnel. A recent paper published in the Journal of Science and Medicine in Sport reported there were 38 deaths in Australia from exertional heat stroke from sport and exercise between 2001 to 2018.
However, exertional heat illness cases are thought to be broadly underreported.
In an effort to reduce the risk of future cases of exertional heat stroke in rugby league, Coroner Lee made recommendations following the inquest into the death of Titmuss.
1) Mandatory 14-day heat acclimatisation training
The human body can adapt quickly (in one to two weeks) to repeated gradual exposure to hot and humid environments, which ultimately reduces the risk of heat illness.
Research shows that pre-season heat acclimatisation protocols reduce the risk of heat illness in team sport athletes.
2) Consider screening and classifying players for exertional heat stroke risk
The United States National Athletic Trainer’s Association recommends players be screened for heat illness when competing in hot and humid conditions.
This process seems intuitive, but we lack a standardised and validated questionnaire.
Other important risk factors include hydration status, prior history of heat illness and/or recent viral illness or infection, body composition (high body fat percentage), and age (older people).
3) Identify cooling strategies that are relevant and effective
Cooling interventions that serve both as a prevention (during play) and treatment (for a victim) should be considered in hot and humid conditions.
In terms of cooling interventions, the evidence suggests cold water immersion, cold water or ice ingestion, cooling garments (such as ice vests or ice towels), portable fans (with or without additional wetting of the skin), or additional breaks in play can help.
The type of sport will influence the decision about which cooling intervention/s are possible.
Other considerations include the level of resourcing (amount of finances and support staff), type of sport (the number of athletes who need an intervention will differ between team vs individual sports) and game demands (continuous exercise vs sports that have regular breaks).
Is there anything else that athletes and coaches can consider?
Many elite sport organisations in Australia and abroad are working with researchers to develop modernised heat policies that look to reduce the risk of heat illness for elite competition.
An example is the revamped Australian Open tennis heat policy.
At the community level, coaches and athletes can consult Sports Medicine Australia‘s online tool. This provides an estimation of risk according to the type of sport and current geographical location.
Sporting and educational organisations should also consider better education for administrators, staff, and athletes to reduce the risk of exertional heat stroke in players.
Samuel Chalmers is a Senior Lecturer at the University of South Australia and receives funding from Rowing NSW, Swimming Australia, Fédération Internationale de Football Association (FIFA), and the National Health and Medical Research Council (NHMRC).
Orlando Laitano is an Assistant Professor at the University of Florida and receives funding from the United States (US) National Institutes of Health (NIH) and the US Department of Defense (DoD). He is a consultant for the Gatorade Sports Science Institute and currently serves as an Associate Editor for the Journal of Applied Physiology.
