Passive heat therapy: A promising preventive measure for people at risk of adverse health outcomes during heat extremes, 2024, Patrick Rodrigues

Abstract
The world is experiencing increased frequency, duration, and severity of life-threatening heat extremes. Most hospitalizations and excess deaths during extreme heat events are associated with pre-existing diseases in older adults. As climate change persists, the global population ages, and the number of individuals with chronic diseases expands, more people are at risk of adverse health outcomes during extreme heat events. Therefore, proactive preventive measures are urgently needed to mitigate heat-related health risks within these populations.

In this context, passive heat therapy (e.g., hot baths, saunas, and water-perfused suits) emerges as a promising countermeasure to improve physiological resilience to a warming planet. Passive heating improves cardiovascular function and overall health in older adults and individuals living with chronic diseases, offering the prospect of reducing cardiovascular strain during hotter days.

Moreover, some studies suggest that passive heat therapy can be an effective strategy for heat acclimation (i.e., improved thermoregulation). This review describes the existing literature on the effects of passive heat therapy on cardiovascular and thermoregulatory responses in individuals with higher heat-related health risks and explores the use of passive heating as a strategy for heat acclimation to mitigate health risks during extreme heat events.

https://journals.physiology.org/doi/abs/10.1152/japplphysiol.00701.2023

 

Not a recommendation for pwME of course, saunas, warm baths and heat suits aren't safe, but I have been trying to acclimatize myself for the last couple of years by not turning on my A/C until I start feeling unwell. I feel this has helped a little with heat resistance and can tolerate much better.

 

Saunas can be tolerated by some with ME but not if they jump in a pool at the end. Sudden cold can trigger OI and its not good to pass out in a pool. Of course I expect some would be made worse, some better, and many not find any improvement. Saunas were part of the treatment I was using in the early 90s. They were briefer than a usual sauna (less than half the time), and finished with a tepid, not cold, shower. I felt a bit better for a day or two. It was just impossible to find any affordable saunas that were open in summer.

 

I think the idea is just to reduce the chance of dying if conditions mean you will be exposed to temperatures not conducive to human health or survival.

Like cold water exposure to lessen the chances of a heart attack if you accidentally fall into cold water, because you work on the deep ocean or you hang out near frozen rivers for survival or by choice.

But I agree that for people whose heat or temperature variations tolerance is the lowest it’s gonna bring on sickness in the acclimatisation phase.

I’d love a light sauna and tepid shower, but also couldn’t get to one. Also probably wouldn’t be offered one since ME isn’t considered much of a vulnerability is it?

 

I set-up a homemade FIR saunas at home around 20 years ago during the cooler months. My heart rate shot up really fast when I got overheated once because I set it up in my bathroom which was too small. I moved the FIR heaters into the kitchen which made it more tolerable. I got some good beads going but felt a bit exhausted after, it did get rid of my neck pain which was good.

I'm less tolerable to extremes. No way I'm jumping into a cool shower after a sauna! I would pass out. I've never tolerated heated pools or whirlpools even before M.E. It lowers my BP for days after.

 

It certainly wouldn't be offered to a pwMS.