Deans' stroke musings: Effect of repeated hot water immersion on cognitive performance, cerebrovascular function, sleep and biomarkers of neurodegeneration in older adults

Changing stroke rehab and research worldwide now.Time is Brain! trillions and trillions of neurons that DIE each day because there are NO effective hyperacute therapies besides tPA(only 12% effective). I have 523 posts on hyperacute therapy, enough for researchers to spend decades proving them out. These are my personal ideas and blog on stroke rehabilitation and stroke research. Do not attempt any of these without checking with your medical provider. Unless you join me in agitating, when you need these therapies they won't be there.

What this blog is for:

My blog is not to help survivors recover, it is to have the 10 million yearly stroke survivors light fires underneath their doctors, stroke hospitals and stroke researchers to get stroke solved. 100% recovery. The stroke medical world is completely failing at that goal, they don't even have it as a goal. Shortly after getting out of the hospital and getting NO information on the process or protocols of stroke rehabilitation and recovery I started searching on the internet and found that no other survivor received useful information. This is an attempt to cover all stroke rehabilitation information that should be readily available to survivors so they can talk with informed knowledge to their medical staff. It lays out what needs to be done to get stroke survivors closer to 100% recovery. It's quite disgusting that this information is not available from every stroke association and doctors group.

Sunday, May 3, 2026

Effect of repeated hot water immersion on cognitive performance, cerebrovascular function, sleep and biomarkers of neurodegeneration in older adults

Ask your competent? doctor if saunas are better than this. And when EXACTLY THEY WILL GET TESTING GOING IN STROKE SUBJECTS!

Effect of repeated hot water immersion on cognitive performance, cerebrovascular function, sleep and biomarkers of neurodegeneration in older adults

Daniel D. Piccolo, Jo Corbett, Thomas B. Williams, Thomas J. James, Janis K. Shute, Mohammad G. A. Alnajjar, Luke C. Hudson, Poppy A. Marsh, Veronika Praskacova See all authorsFirst published:

29 April 2026

https://doi.org/10.1113/EP093500Digital Object Identifier (DOI)

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Handling Editor: Toby Mundel

Funding information:

The authors gratefully acknowledge funding by SPATEX and the British and Irish Spa and Hot Tub Association (BISHTA) Grant Number: 00229288; and the Ceperich Educational Trust.

Abstract

Ageing is associated with cognitive decline and increased risk of developing neurodegenerative disease. Repeated passive heating, using hot water immersion (HWI), may improve cognitive performance via improved cerebral oxygenation, but this is yet to be examined in older adults. Twelve healthy older adults (aged: 69.2 ± 10.0 years; body mass index: 25.2 ± 4.1 kg m−2) completed a 6-week pre–post intervention study consisting of two to three weekly 1 h HWIs in 40°C water. Rectal temperature was maintained in a target range of 38.5–39.0°C during HWI. Cognitive performance (working memory via 1 and 2-back, inhibition via 2-choice reaction time, logical reasoning via logical relations) and cerebral oxygenation (Δoxyhaemoglobin, Δdeoxyhaemoglobin, Δtotal haemoglobin and Δtissue saturation index) were assessed during the first and final HWI sessions (pre-, immediately post- and 3 h post-HWI). Common carotid artery blood flow (CCA-BF), sleep quality (7-day baseline and final week), plasma [amyloid-β] 42 (Aβ42), and [phosphorylated tau] (p-tau), were measured pre- and post-intervention. Repeated HWI improved 1-back (P = 0.023) and logical reasoning (P = 0.002) performance, but not 2-back or 2-choice reaction time (P > 0.05). Cerebral oxygenation was acutely reduced immediately post-HWI (all parameters P < 0.05), but returned to baseline 3 h post-HWI, with no chronic adaptation. CCA-BF, sleep quality, [Aβ42] and [p-tau] all remained unchanged at 6 weeks (P > 0.05). Repeated HWI improves cognitive domains of logical reasoning and working memory without altering cerebral oxygenation, CCA-BF, sleep or neurodegenerative biomarkers. Further investigation into the underlying mechanisms for cognitive performance improvements via HWI is warranted.

ageing, exercise mimetic, passive heat therapy, working memory

Highlights

What is the central question of this study?
Can 6 weeks of hot water immersion improve cognitive performance, cerebrovascular function, sleep and neurodegenerative biomarkers in healthy older adults?
What is the main finding and its importance?
Six weeks of two to three hot water immersions per week improved working memory and logical reasoning in healthy older adults, but did not alter common carotid artery blood flow or oxygenation, sleep, or neurodegenerative biomarkers. The results suggest that hot water immersion may offer a simple, non-pharmacological, therapeutic approach to support cognitive performance in older adults, though mechanisms remain to be clarified.