How to take your temperature on your iPhone by using a Kinsa smart thermometer

You can take your temperature using your iPhone by linking a smart thermometer like Kinsa's QuickCare and Smart Ear products.

How to tell if you have a fever without a thermometer

If you don't have a thermometer, you can still gauge if you have a fever by looking for fever-associated symptoms like chills and body aches.
CNET

Here's the Right Temperature for Your Thermostat in the Winter

In the winter, experts recommend that you set your thermostat to 68 degrees Fahrenheit when you're home, and 60 to 65 degrees when you're asleep or away.