New ways to help people with MS combat heat related fatigue

Associate Professor Ollie Jay

The University of Sydney, NSW

| Better treatments | Social And Applied Research | Project | 2018 | Investigator Led Research |


Approximately 90% of Australians with MS are affected by the heat, which can lead to heat-induced or heat-related fatigue. Heat-related fatigue can result in loss of employment and significant increase in the cost of living.

Recently, Associate Professor Ollie Jay and his team have shown that if certain parts of the body are cooled, the sensation of fatigue can be reduced, allowing physical activity in the heat to be performed for longer periods of time. In this project, he aims to build on these findings and develop simple and novel interventions for preventing heat-related fatigue in people with MS.

Associate Professor Jay will assess if swirling cold fluids in the mouth is enough, or if they need to be swallowed. He will also test whether particular skin sites can be targeted with surface cooling materials to reduce heat-related fatigue, and if methanol can be rinsed in the mouth or applied to the skin to reduce heat-related fatigue.

The results from these experiments will lead to the development of novel cooling interventions that are simple and inexpensive. Ultimately, the findings of this study will not only help people with MS maintain their functional capacity for longer during exposure to the heat, but also help us better understand the underlying mechanisms associated with heat sensitivity in MS.

Progress to Date

Associate Professor Jay and his team have completed data collection for the first of three studies planned in total. Information has been recorded from 21 participants who completed three experimental trials for this study.

Preliminary findings have shown that cold water swilling does not measurably improve health-related fatigue or increase exercise capacity in the heat in people with MS with heat sensitivity. This observation has led to the investigators changing the next part of their experiment to a different intervention. Associate Professor Jay will instead test alternative methods to alleviate heat related fatigue in MS: namely, aspirin, and a menthol spray to cool the skin.  Due to unforeseen factors, including the COVID-pandemic, these have been difficult to source and have delayed study progression. The research team is hoping to address these issues in 2022 and restart the timeline.

Despite the change in direction based on early findings, Associate Professor Jay’s work will result in clarity on ways people with MS can combat heat-related fatigue. Enrolment of patients in 2021/2022 has been significantly affected by the COVID-19 pandemic. The study has been extended to allow more time to complete the remaining aims and objectives.


  • Chaseling GK, Filingeri D, Allen D, Barnett M, Vucic S, Davis SL and Jay O (2021) Blunted sweating does not alter the rise in core temperature in people with multiple sclerosis exercising in the heat. Am J Physiol Regul Integr Comp Physiol, 320(3);R258-R267.
  • Chaseling GK, Allen DR, Vucic S, Barnett M, Frohman E, Davis SL and Jay O* (2019) Core temperature is not elevated at rest in people with relapsing-remitting multiple sclerosis. Mult Scler Relat Disord; 29:62-67.
  • Allen DR, Huang M, Morris NB, Chaseling GK, Jay O and Davis SL* (2019) Impaired thermoregulatory function during dynamic exercise in multiple sclerosis. Med Sci Sports Exerc; 51(3):395-404. Editor’s pick - February, 2019.
  • Christogianni A, Bibb R, Davis SL, Jay O, Barnett M, Evangelou N, Filingeri D (2018) Temperature sensitivity in multiple sclerosis: An overview of its impact on sensory and cognitive symptoms. Temperature; 5(3):208-223.
  • Davis SL, Jay O and Wilson TE (2018) Thermoregulatory dysfunction in multiple sclerosis. In: Handbook of Clinical Neurology, Thermoregulation: From Basic Neuroscience to Clinical Neurology, Part II, Romanovsky AA (Ed) Elsevier BV

Updated: 31 March 2022

Updated: 05 January, 2018



  • Associate Professor Michael Barnett
  • Associate Professor Scott Davis
  • Dr Davide Filingeri
  • Associate Professor Anthony Carlsen

Grant Awarded

  • Project Grant

Total Funding

  • $176,000


  • 3 years

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New ways to help people with MS combat heat related fatigue