Pool Temperature - Health Question

ForeverSwimForeverSwim Pittsburgh, PennsylvaniaCharter Member
edited May 2014 in General Discussion
I had an interesting experience last week while training, when a mid-50’s lifeguard at the local pool was turning 60-70 aged swimmers away by telling them how cold the pool was at 75F, when it was normally 83F. This was aggravating because discussions were brought up on the deck that these people could suffer heart attacks at that temperature, and to not risk training in such cold temperatures. Now, I understand I am a polar bear, but I couldn't believe what I was hearing.

Question: Is there more of a risk of injury doing moderate training, all factors equal, in water that is 83F, or water that is 75F? Let's keep this conversation to the risk of heart attack for 'older' swimmers - at which temperature are they more susceptible to injury?

I am intrigued by this, and would love to present any factual findings to the board.

Pittsburgh, Pennsylvania U.S.A.



  • loneswimmerloneswimmer IrelandCharter Member
    edited January 2014
    As I've previously read or recall in some papers, cold water (undefined I'll have to find the actual figures but I think 68F/20C is the high end) immersion in an unhabituated person carries a maximum 5% chance of cardiac arrest, regardless of age, ie. someone with no experience at all. 5% would be too high for a pool but I honestly think that is for a figure in the 40s range. I can try and find some of the studies later, but Tipton & Golden are the experts in this area.

    Edit 1: I wrote a related blog post last night, about the different process in action when you enter cold water. Here's http://www.port.ac.uk/uopnews/2012/05/30/scientists-warn-swimmers-of-heart-attack-risk/, Uni of Portsmouth where he and Frank Golden are based, on the risks. As is often the case, I think we'll find that the definition of cold, as your starting point, is absent or implied.

    Edit 2: I have a few papers on cold I refer to regularly inc Tina Maakinen's Human Cold Exposure Adatation, Tipton et Al Human Physiological Responses to Cold Exposure, . But in the latter there is this sentence:

    When muscle glycogen is depleted prior to cold exposure (resting in 18°C water), thermo-
    regulatory function is unimpaired, and a greater reliance on lipid oxidation may permit continued shivering thermogenesis.

    This implies to me that Tipton (a global expext) and the other authors are saying 18C is NOT cold water as it's possible to maintain thermogenesis in such temperatures. So you could hypthesise 18C/64F as your lower limit.

    A NASA paper; Acclimatization to Cold in Humans, 1989:

    Thus, a man immersed in relatively cold water (22"C), loses very little heat from the hands and feet, a result of the greatly reduced tissue conductance in the extremities; much more heat is lost from the trunk because of high tissue conductance to this body area.

    That's 71F, within a margin of your 75F.

    Edit 3: However... in Immersion deaths and deterioration in swimming performance in cold water by Tipton & Golden, 1999, who literally wrote the book on sea survival, they tested swimmers at three temperatures, 25C, 18C, & 10C, where 10C is considered cold water, and more in line with what we all consider cold.

    The Interpretation states: Impaired performance and initial cardiorespiratory responses to immersion probably represent the major dangers to immersion victims. Consequently, treatment should be aimed at symptoms resulting from near-drowning rather than severe hypothermia.

    All ten swimmers completed 90 min swims at 25°C, eight completed swims at 18°C, and five at 10°C. In 10°C water, one swimmer reached swim failure after 61 min and four were withdrawn before 90 min with rectal temperatures of 35°C when they were close to swim failure. Swimming efficiency and length of stroke and swim angle increased more in 10°C water than in warmer water. These variables seemed to characterise impending swim failure.

    Edit 4: In a paper by the same authors, in 1989, Human Adaptations to Repeated Cold Exposures, the figure for cold water testing was 15C/59C.

    So I think given these papers, 3 out of 4 define cold as 18 or lower. So that's our starting point and your point of reference for cold.

    Edit 5: I'm doing this as much for my own fun as @SwimForever, looking for a definition of cold water outside the OW swimming community is something I've been meaning to do for a while.

    Edit 6: In Temperature dependence of habituation on the initial responses to cold water immersion Tipton & Golden, 1998. (those two names again) defined cold water for testing as 10C, with a reduction in the measured responses (specifically respiratory rate and heart rate) at 15C.

    In NONE of these studies is any mention made of cardiac risk during testing, nor of the selection method of the various groups, which I imagine would have been pre-screened to remove anyone with a known risk factor.

    Here's an important line from that study: Coldshock response is probably responsible for the majority of the 400-1000 UK civilian annual open water deaths. And that's in the context of having defined cold water as 10C (40F). Given that 15C saw a measured reduction, it's feasible to conclude that 25C/77F is far outside the range of being considered cold. In fact thermo-neutral water is 30 to 34F, but human thermal neutrality is achieved in water 4C colder than that. That's somewhere in another study, but that puts thermally neutral water for a swimmer at 26C/79F.


  • I know the risk of me being annoyed, redfaced and slower than usual is MUCH higher when the water temp goes above 80F.
    It's insane for someone,presumably with no medical training besides that which is required for being a lifeguard, could say that 75 F is "cold" and unsafe.
  • AnthonyMcCarleyAnthonyMcCarley Berwyn, PACharter Member
    edited January 2014
    There is an outdoor 50 meter pool out my way (Martin’s Dam) that is creek fed and without a heater. It is only open during the summer season, but still often goes into the 60’s. Most of the people I have seen there are even older than I am… never seen a heart attack.

    And out your way, North Park pool isn't heated. The couple of times I have been there it was full of people over 60. I didn't see a flush of heart attacks there either.
  • IronMikeIronMike Northern VirginiaCharter Member
    My last pool, the only one I really had access to, had a time where they kept it at the upper 80's. I complained, but they kept saying, "for the kids!" They wouldn't return it to the mid-70's until I forwarded them some articles about what happened to Fran Crippen (RIP). Then they turned the heat back down.

    We're all just carbon, water, starlight, oxygen and dreams

  • When it comes to the water temperature, how hot is too hot?
    IronMike wrote:
    My last pool, the only one I really had access to, had a time where they kept it at the upper 80's. I complained, but they kept saying, "for the kids!" They wouldn't return it to the mid-70's until I forwarded them some articles about what happened to Fran Crippen (RIP). Then they turned the heat back down.

    For those who don't know the sad story about Fran Crippen here is an excellent article
    that asks questions regarding high water temperatures.

  • They did the same thing at my pool... closing because it was 75. But if it was 88 in the summer, they won't even turn the cooling sprinklers on. I know this is an outdoor pool, but my college pool was kept at 74 constantly. I think for times to count in Olympic competition, it has to be 72-74. ( I know it's a specific temp, it's not in the. 80s).
    I was still warm getting out in the 75 degree pool... I don't get it .
  • swimchica623swimchica623 Member
    edited January 2014
    Thanks... knew it was in the 70s. Thought it was below 75 though! My thermometer might be a bit screwed, but still....my point is...if pools HAVE to be at 77-82 for FINA approved competition and so many are kept much warmer...they shouldn't be sending people away because of 2 degrees.
  • I spent most of 2017 training in a pool that got hotter and hotter as the year went on. It started at 83 and had reached 88F by the time they finally fixed the temperature control unit. It was a miserable experience, especially because I was trying to train for a 10k lake swim.

    I am convinced that swimming in water that warm contributed to my worsening shoulder issues, which just requires surgery. It wasn't the only factor, but it didn't help. Hot yoga class participants often overstretch and injure themselves in the heat. The same thing happened to several people in my workout group.

    When I return to swimming - and I will - I think I'll stick to the Pacific ocean.

  • BridgetBridget New York StateMember

    Warning- cold water weenie chiming in. Actually, I'm just not a fan of the get wet process at ANY temperature, but I will say that FOR ME, an Eighty Degree F pool indoors feels to me like a low seventies lake, or a mid sixties ocean. My pool at work is usually low eighties, and I do some mileage, and know that the warmer feel later in my workout will peeve me a bit, but I figure that will keep me from blowing out my shoulders as I boost miles- when I hit the lake in early spring, the Fifties will keep me from injury by way of being an all body ice pack. ;)

    Now, I've swum in pools indoors that were in the mid to low seventies, and had a major problem warming up, even after a mile. That's me. My issue with the "keep the old people out" policy is that as you all pointed out, cold is great for many. I'd put a sign saying the usual temperature, the current temperature, and warn that the water may be challenging for some swimmers, and maybe restrict cannonball entry. ;) More than cardiac concerns, I'd want guards to be watching for hypothermia for those not used to the cold- especially after getting out. Some swimmers try to equate water temperatures to air temperatures and can't imagine that water in the seventies can feel cold. . . until they try it- then the new to swimming swimmers get that water temperature and body temperature is what matters. Pre-acclimatizing.

    Further caveat- I've worked a lot with the senior population in aqua fitness, and the Arthritis Foundation has low eighties guidelines for their aqua classes. My classes might get cranky at lower temperatures than that, and some may opt out, but they have always agreed that they were old enough to make up their own minds. My current work pool has a malfunction, so classes were canceled due to cold, then due to lack of proper function, so I took my day off and swam six mile in Lake George at just under Seventy. Life is good.

  • dpm50dpm50 PA, U.S.Senior Member

    I had to laugh when I saw that "60-70." I'm in my late 60s and that temp sounds just fine. I swam in Aquatic Park fo the first time this year and chose not to wea r my wetsuit. Good thing. A woman I'd guess to be in her 80s had just emerged from the water. She told me she swam just about every day. And while it took a little gething used to, I enjoyed my lowest temp without a wetsuit swim.

    It's silly to assume things about ppl in a particular particular age group, whether 20-30 or 60-70. As Bridget says, simply put up a sign saying what the temp I s and let swimmers decide whether it's too low. The water heater broke at my Y last winter, and the temp was a "cold" (lol) 78.

    People were given that info at the front desk and made their own choice. (Actually, I was a little disappointed to see it was still crowded, but c'est la vie!

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