Apple Watch Series 8: What the New Temperature Sensor Can and Can't Do

Speaker 1: The Apple Watch has gained yet another health sensor. The series eight and Ultra are the first Apple watches to measure wrist temperature. Adding to the growing number of health metrics these devices can collect, but don't think of the Apple Watch Series eight like a thermometer. Instead of taking spot readings, it passively measures your wrist temperature overnight during sleep, there are many things that can impact your temperature. Apple mentions a few of them in its Apple Watch announcement from September, jet lag exercise or illness for [00:00:30] example. But one of the biggest reasons Apple put a temperature sensor in the watch is to help you monitor your monthly cycle and ovulation window. The series eight and ultra can predict when you last ovulated based on fluctuations in your wrist temperature. Overnight only time will tell how useful the temperature sensor truly is. But here's a closer look at how it works and its potential benefits. Speaker 1: The Apple Watch Series [00:01:00] eight and Ultra have two temperature sensors once it's underneath the screen and the other sits on the watches underside closer to your wrist. Together, these sensors should cancel out environmental factors to provide an accurate reading of your wrist temperature. Apple says the watch can sample wrist temperature every five seconds and it can detect changes as small as 0.1 degrees Celsius. Apple takes this temperature data and then presents it in a chart in the health app on your iPhone. From here, you can see how [00:01:30] last night's risk temperature compares to your baseline. You can also look at comparisons from the last month, week, or past six months, but you must wear your Apple Watch to sleep for at least five nights with sleep tracking enabled before seeing any of these readings. Although you can see individual temperature readings by digging into the health app, the Apple Watch isn't meant to be used like a thermometer. Instead, it's meant to show you whether your temperature might be higher or lower than your normal baseline. The more data these devices gather about our [00:02:00] bodies, the more important privacy is. Apple says Data stored in the health app is encrypted when your phone is locked with the passcode touch ID or face id. The same goes for data stored in iCloud. You'll also want to make sure two factor authentication is turned on for your iCloud account, which ensures that even Apple can't read or access your health data. Speaker 1: You might be wondering what ovulation has to do with your temperature. Ovulation causes your body temperature to rise, so tracking body temperature could [00:02:30] help you estimate when you may be fertile. The Apple Watch combines data from its temperature sensors with its algorithms to determine when ovulation was likely to have occurred. Speaker 2: Your resting temperature goes up by a very small but noticeable amount around the time of ovulation stays elevated in that second half of the cycle. And then if not pregnant drops and you got a period when women are pregnant, the basal eye temperature stays. High Speaker 1: Devices like the Apple Watch could be helpful for tracking ovulation because [00:03:00] they provide more personalized insight based on what's happening in your own body. That's important because ovulation can vary depending on the month or the person. Speaker 3: So if you can establish a pattern or potentially see how your individual pattern may fluctuate with outside stressors, um, that's really helpful information and you can even present that if you're having difficulty trying to conceive. You can present this data to, um, a healthcare [00:03:30] expert to see how they may interpret it and, and be able to assist you with that Speaker 1: Before their recycle tracking apps and temperature sensing devices like the Apple Watch and the Aura ring, which also has a temperature sensor. The fertility planning process was pretty old fashioned. Speaker 2: You basically would take your first morning temperature as soon as you woke up, ideally with no activity at all and plot it out on graph paper and basically try to note the um, rise. It happens mid-cycle fertility Speaker 1: Tracking isn't the only reason [00:04:00] why tracking your cycle and ovulation patterns can be useful. Changes in menstruation could in some cases indicate other health conditions. Speaker 3: There are several different things that can affect ovulation. One of the most common is polycystic, uh, ovary syndrome, which if you are not, um, mestre weighting on a regular fashion there more than likely should be some adjustments to, to your, um, lifestyle and potentially, um, medications needed [00:04:30] to help adjust that. So, so this temperature, um, graphing and, and knowledge of your temperature can be a measure of your overall health as well. Speaker 1: But it's also important to remember that the Apple Watch is not a medical device and shouldn't be used for diagnosis. Apple cycle tracking features and retrospective ovulation estimates also should not be used for contraception, can Speaker 2: Be helpful for family planning purposes, but by no means is adequate form of contraception. So, [00:05:00] um, I stress that, you know, women who are trying not to get pregnant should not use this because A, there can be errors in the data and B, you can have a cycle that is variable, um, that may not follow the regular pattern. Speaker 1: Since temperature sensing is so new to the Apple Watch, it's unclear just how useful it is yet whether you're using it for fertility planning or not. Right now, it feels like it's largely up to the wear to make sense of all this temperature data. Aside from cycle tracking and retrospective ovulation [00:05:30] estimates, risk temperature doesn't seem to be factored into other health insights. I love to see Apple do something similar to Aura, which makes a smart ring of the same name that can measure activity, sleep and skin temperature, among other things. Skin temperature is one of the many factors that contribute to aura's readiness score, which helps you decide whether you should take a rest or hit the gym. Fitbit also launched a similar feature last year. I would love to see Apple take a similar approach and find new ways to incorporate the Apple [00:06:00] Watch's risk temperature readings into other features in the future. Thanks for watching and I'll see you next time.