Apple Watch Series 8 Takes Five Nights to Establish Baseline Wrist Temperature

[MacRumors]

Apple today published a new support document with additional details about the new wrist temperature sensing feature available on Apple Watch Series 8 and Apple Watch Ultra models, and it turns out the feature requires users to wear their watch for five nights before it can detect a baseline temperature.

Apple Watch Series 8 and Apple Watch Ultra have two temperature sensors — one on the back crystal, near your skin, and another just under the display. While the wearer sleeps, Apple Watch samples wrist temperature every five seconds. This design improves accuracy by reducing bias from the outside environment, according to Apple.

Your body temperature naturally fluctuates and can vary each night due to your diet and exercise, alcohol consumption, sleep environment, or physiological factors such as menstrual cycles and illness. After about 5 nights, your Apple Watch will determine your baseline wrist temperature and look for nightly changes to it.

Apple says that Sleep must be set up with "Track Sleep with Apple Watch" enabled, and Sleep Focus must be enabled for at least four hours a night for about five nights. After that, users can check Body Measurements -> Wrist Temperature in the Health app for recorded measurements.

Apple cautions that the feature isn't a medical-grade device and shouldn't be used for any medical purpose, nor is it a thermometer, and it cannot provide measurements on demand. A loose-fitting Apple Watch can also impact wrist temperature data.

Apple is marketing the feature in promotional materials for the new Apple Watch models as a way to improve period predictions and retrospective ovulation estimates, but the support document suggests that tracking nightly temperature changes while sleeping can give anyone insight into their "overall well-being."

For those who have no use for the feature, Wrist Temperature can be turned off in the Watch app on iPhone, under Privacy -> Turn off Wrist Temperature.

Article Link: Apple Watch Series 8 Takes Five Nights to Establish Baseline Wrist Temperature

 

[Corsig]

So it won’t alert me if I have a fever?

 

[Le0M]

Honest question:
If I wear the watch all day, and put it into charge before going to sleep, how can I possibly be wearing it at night?

 

[YEMADOLIA]

So it won’t alert me if I have a fever?

Not likely
Maybe future iterations but not this year. The lady spoke as if the problem isn’t necessarily software but rather hardware accuracy.

 

[GTPprix]

Honest question:
If I wear the watch all day, and put it into charge before going to sleep, how can I possibly be wearing it at night?

Came here to ask this as well. I dont sleep with mine on because obviously it has to get charged at some point and a watch doesnt do me much good on a charger during the day?!

 

[PowerButton]

I just wish it could last 5 nights on a single charge… 🤔

 

[performa_6400]

For those that wear your watch overnight, when do you charge it?

 

[dz5b609]

Honest question:
If I wear the watch all day, and put it into charge before going to sleep, how can I possibly be wearing it at night?

Because there's quick charging on the newer ones which means that 15-30 minutes of charging in the evening will get you through the night and 15-30 minutes of charging in the morning (while showering for example) will get you through a day (because it will still be pretty charged from that evening 15-30 minute charge).

Added bonus of that is that's very good for your battery health.

 

[whoknows2597]

Came here to ask this as well. I dont sleep with mine on because obviously it has to get charged at some point and a watch doesnt do me much good on a charger during the day?!

What I do, take off my watch an hour or so before my bedtime then do my evening routine. After that time, it should be 80% to 100% charged then I wear my watch when sleeping. In the morning, I place it on the charger and leave it there before I head out to work.

 

[wallinbl]

For those that wear your watch overnight, when do you charge it?

My wife sleeps with hers on, and she charges it when she's in the shower.

 

[james2538]

Honest question:
If I wear the watch all day, and put it into charge before going to sleep, how can I possibly be wearing it at night?

I’ve been using my S6 for sleep tracking. I just throw it on the charger whenever I’m in the shower/getting ready. Thats roughly 30 min in the morning and 30 min after my workout. Enough to keep it from dying.

 

[addamas]

Came here to ask this as well. I dont sleep with mine on because obviously it has to get charged at some point and a watch doesnt do me much good on a charger during the day?!

I charge my S7 after morning coffee, when start work next on computer, when take bath or Watch a movie at night depending on my calendar.

10% to 100% was taking +- 45 mins plugged to windows laptop with usb-c

S7 and newer allows fast charging but only using usb-c

 

[james2538]

Sounds like they don’t even use the temperature sensor to estimate which sleep stage you’re in. Like for men it does nothing except show deviations that you must manually look at in the Health App. The data isn’t used elsewhere.

I may still end up buying an S8 as the price difference with the veteran’s discount isn’t huge and I’d like the car crash detection (along with the S7 bigger screen).

Still such a disappointing update from Apple.

 

[notabadname]

For those that wear your watch overnight, when do you charge it?

At work, while sitting at a desk. 45 minutes to 80% or 75 for 100%. It doesn’t need an overnight period to charge, and sleep tracking is more important to me than knowing my heart rate or activity at my desk. I know people that do it on their drive to work (you could even split the charging between the to and the from work, if you drive under 40 minutes. Most of us simply have an hour of “idle“ time in which we can charge the watch.

 

[andreagrandi]

For those that wear your watch overnight, when do you charge it?

In the morning. I still have 40-45% battery left in the morning and the fast charge recharges it in less than 1 hour so I can take a shower, have breakfast etc.. then I wear it again until next morning (I have a Watch 7)

 

[dubvulture]

For those that wear your watch overnight, when do you charge it?

I charge my S6 in the car on my way to and from work.

 

[Apple_Robert]

Honest question:
If I wear the watch all day, and put it into charge before going to sleep, how can I possibly be wearing it at night?

It only takes 30-45 mins to charge. Put it on the charger a little earlier. Problem solved.

 

[MayaUser]

It only takes 30-45 mins to charge. Put it on the charger a little earlier. Problem solved.

he was talking about these 5 nights...if you take it from your wrist....you reset the whole thing ?!
If yes, this is irrelevant since the battery life dont last 5 nights
If the algorithm can pause and resume then this can be done.

 

[raziel101]

For those that wear your watch overnight, when do you charge it?

When I shower in the morning morning and night.

 

[PinkyMacGodess]

Wow, that really seems silly. FIVE NIGHTS? And if you can't stand things on your wrists while sleeping? Wow...

Be careful what you wish for? And what will it do? Just report temps outside of a range? And if people sleep 'hot', then the upper end is way too high. Seems that sensor has even more questionable value. *shrug*

It seems to me like something that sets a range for heart rate and for me would be a joke. I peaked at 171bpm yesterday and usually am in the upper 160's working out. Sure, rates past 200 for anyone isn't a good idea, but if I'm sitting doing nothing and my rate spikes into that upper range, that IS A PROBLEM, and I should be warned (especially if I was sleeping). *shrug*

 

[madsci954]

For those that wear your watch overnight, when do you charge it?

I shower in the evening, I take mine off and set it on the charger shortly before that. By the time I’m done and ready for bed, it’s fully, if not at least 90%, charged.

 

[tridley68]

For those that wear your watch overnight, when do you charge it?

Lunchtime for me.

 

[oneteam]

Honest question:
If I wear the watch all day, and put it into charge before going to sleep, how can I possibly be wearing it at night?

I normally charge it in the evenings and wear to bed and the following day until I complete all my circles, then I charge it.

 

[alexandr]

For those that wear your watch overnight, when do you charge it?

When do you charge your phone?

 

[notabadname]

I have an Oura ring that does sleep and temperature tracking. It is incredibly accurate in regards to temperature, even told me when I had COVID - simply that I may be coming down with an illness - more than a day before I felt symptoms. The Oura ring requires 30 days of wear to calibrate to your body’s norm. 5 days is pretty minor for the watch.