iwatch 8 Body temp not working

Fredsjunk,

It's my belief that I can get this working for you! Including my own watch, I've helped several others on this forum.

I only need to know one thing first...

Did you find where it MIGHT say, "Five more nights"?

Is that what it says?

I can't give you the steps for sure because mine is working now and the message is gone. I believe...

Open the Health app on the paired iPhone.

Click "Browse" in the lower right corner of the screen. Click on "Body Measurements".

Look for "Wrist Temperature" and possibly click on it (mine shows my baseline temp). I believe that a chart will open and at the top of the chart it will say "Not enough data". Look below the chart and see if you see, "5 more nights".

Also, the front temperature sensor is for comparison to what the wrist temperature sensor is reading. Then there is an algorithm used by the software to determine and record 'good' measurements.

Screenshot Source: Track your nightly wrist temperature changes with Apple Watch - Apple Support

Hello Fredsjunk,

Thank you for using Apple Support Communities. We'd like to share some information and steps to see if we can get this issue sorted out. First, review the following resource an confirm that the following settings are set up correctly: Track your nightly wrist temperature changes with Apple Watch - Apple Support

Here's what you need

-Sleep must be set up with Track Sleep with Apple Watch enabled.

-Sleep Focus must be enabled for at least 4 hours a night for about 5 nights.

-Sleep Tracking must be performed for about 5 nights

-Sleep Schedule must be set up for Sleep Focus. (only using manual start for Sleep Focus will not track Wrist Temperature)

The resource also suggests to make sure that your Apple Watch fits just right. If it's too loose, it can impact wrist temperature data.

Additionally, if you have any pending updates available on your Apple Watch and your companion iPhone, please install them. Keeping your devices fully updated can help sort out unexpected behaviors. Just in case, the resources below can guide you through the update process:

1.) Update Apple Watch.

2.) Update iPhone.

Feel free to keep us posted on your results. Thank you for using Apple Support Communities.

Hello Fredsjunk,

On your iPhone when you go to Health > Body Measurements > Wrist Temperature, are you seeing this message? "Available After X More Nights” where “X” is the number of days. If so, your Apple Watch must be worn overnight consistently until this number reaches zero to begin measurements.

If not message is found, please continue below.

Check out the link below to check if Sleep Tracking is being performed.

Track your sleep on Apple Watch and use Sleep on iPhone - Apple Support

To perform the recommended troubleshooting steps via the link above, complete the steps in the section titled "View your sleep history."

Based on your iPhone usage at night, Sleep on iPhone tracks and charts your Time In Bed. To receive sleep data from Apple Watch, sleep tracking must be enabled for at least 4 hours each night. 

To view your sleep history, open the Health app on your iPhone, tap Browse at bottom of the screen, then tap Sleep. If you have Sleep saved as a favorite, you can access it from the Summary page in the Health app.

The bar graph by default is set to D for daily. Tap W at the top of the chart to view your sleep history for the past week, M for the past month, or 6M for the past 6 months. Tap Show More Sleep Data and select a category to review additional sleep details.

*Stages: View the time and percentage you spent Awake or in REM, Core, or Deep sleep.

*Amounts: View your Sleep Duration details such as Average Time in Bed and Average Time Asleep.

*Comparisons: View your Heart Rate and Respiratory Rate in relation to your time spent asleep. If you have Apple Watch Series 8 or Apple Watch Ultra, you can also compare changes in your nightly wrist temperature data.

We recommend the steps above because they will show you how to track your Sleep on your Apple Watch and use Sleep on your iPhone.

As for your question regarding the front-facing sensor on your Apple Watch, we're unable to say explicitly without having more context about the conversation that took place at the Apple Store.

Please do not hesitate to contact us if you have questions or need any additional support.

Thanks for using the Apple Support Communities.

Cheers!