3 ms·

Yeah I have been collecting these stats on my own devices about their operating temperatures and I'm often surprised how much smaller the range is than I was ex

Yeah I have been collecting these stats on my own devices about their operating temperatures and I'm often surprised how much smaller the range is than I was expecting. For example: Kobo eReader: 0 - 45C Pixel 6: 0 - 35C Macbook Pro: 10C - 35C Pixel Buds: 0 - 35C Garmin heart rate strap: 0 - 40C Garmin bike computer: -20 - 60C From talking to manufacturers I often hear "it will probably work outside this, but you'll have worse battery performance and eventually issues will arise". Another thing I hear is that, below zero, for wearable devices they will often stay at an OK temperature if they are in a pocket or beside your body.

wongarsu 3y ago
Garmin's strategy makes sense: a heart beat strap benefits from your body's temperature regulation, both to keep cool and keep warm; a bike computer has to take what it gets, but at least gets a lot of convection to keep temps reasonable when it sits in the sun. I'm most surprised that a MacBook Pro with its active cooling doesn't have a higher max temp than a smartphone.
- mrguyorama 3y ago
  Active cooling effectiveness depends significantly on the delta between incoming temperature and the heat source temperature, and the relationship is worse than linear I think.
  - SAI_Peregrinus 3y ago
    Newton's Law of Cooling shows it's an exponential decay in heat transfer rate as the delta decreases.[1] [1] https://en.wikipedia.org/wiki/Newton%27s_law_of_cooling https://en.wikipedia.org/wiki/Newton%27s_law_of_cooling
    - mrguyorama 3y ago
      That was my intuition but it's not my field and I'm too lazy to look it up so I really didn't want to spread more precise but less accurate info.
- chrisfosterelli 3y ago
  My concern about Garmin's strap was mostly that I do a lot of running below 0 in the winter but to their credit their support was very helpful and said it was unlikely to actually damage the HRM device given the conditions I described -- they even offered to send me some free batteries since I might go through them quicker.
  - NoZebra120vClip 3y ago
    In 2019, Chris Siebenmann discovered that the bitter Canadian winters were taking a toll on his desktop machine at home: https://utcc.utoronto.ca/~cks/space/blog/tech/ColdLockupMachineMystery https://utcc.utoronto.ca/~cks/space/blog/tech/ColdLockupMach...
AdamH12113 3y ago
The earbuds seems particularly odd given that an ear canal is close to human body temperature (~36C) to begin with.
- xnyan 3y ago
  The human body is ~36C only internally. I just used an IR thermometer, and the inside of my ear canal is currently 32C, plus a large portion the earbud is external to your ear canal. EDIT: Out of curiosity I also measured the temperature of my airpod at the ear canal tip - 27C.
  - brnt 3y ago
    The human body varies and it may also be 37.5C. Sick people even more. Might still want to use earphones. Ear canals get pretty close to core temp, as they're near the brain. If you're measuring 32C either you are in a cold environment or you might be misaiming (these things aren't that easy to use, or very accurate). In a warmer climate, the delta gets even less. So yeah, it's a bit surprising that wearables aren't rated for body temperature.

wongarsu 3y ago

Garmin's strategy makes sense: a heart beat strap benefits from your body's temperature regulation, both to keep cool and keep warm; a bike computer has to take what it gets, but at least gets a lot of convection to keep temps reasonable when it sits in the sun. I'm most surprised that a MacBook Pro with its active cooling doesn't have a higher max temp than a smartphone.

mrguyorama 3y ago
Active cooling effectiveness depends significantly on the delta between incoming temperature and the heat source temperature, and the relationship is worse than linear I think.
- SAI_Peregrinus 3y ago
  Newton's Law of Cooling shows it's an exponential decay in heat transfer rate as the delta decreases.[1] [1] https://en.wikipedia.org/wiki/Newton%27s_law_of_cooling https://en.wikipedia.org/wiki/Newton%27s_law_of_cooling
  - mrguyorama 3y ago
    That was my intuition but it's not my field and I'm too lazy to look it up so I really didn't want to spread more precise but less accurate info.
chrisfosterelli 3y ago
My concern about Garmin's strap was mostly that I do a lot of running below 0 in the winter but to their credit their support was very helpful and said it was unlikely to actually damage the HRM device given the conditions I described -- they even offered to send me some free batteries since I might go through them quicker.
- NoZebra120vClip 3y ago
  In 2019, Chris Siebenmann discovered that the bitter Canadian winters were taking a toll on his desktop machine at home: https://utcc.utoronto.ca/~cks/space/blog/tech/ColdLockupMachineMystery https://utcc.utoronto.ca/~cks/space/blog/tech/ColdLockupMach...

AdamH12113 3y ago

The earbuds seems particularly odd given that an ear canal is close to human body temperature (~36C) to begin with.

xnyan 3y ago
The human body is ~36C only internally. I just used an IR thermometer, and the inside of my ear canal is currently 32C, plus a large portion the earbud is external to your ear canal. EDIT: Out of curiosity I also measured the temperature of my airpod at the ear canal tip - 27C.
- brnt 3y ago
  The human body varies and it may also be 37.5C. Sick people even more. Might still want to use earphones. Ear canals get pretty close to core temp, as they're near the brain. If you're measuring 32C either you are in a cold environment or you might be misaiming (these things aren't that easy to use, or very accurate). In a warmer climate, the delta gets even less. So yeah, it's a bit surprising that wearables aren't rated for body temperature.