- So there's a new ritual that a lots of us share right now.

Checking our temperature to see if we have a fever.

And it's understandable.

Fever's are common symptoms of COVID-19.

But if you're hoping your temperature is a nice 98.6 degrees

or 37 Celsius.

You might learn something new about yourself.

- 97.25.

- 98.2.

- 97.1.

- Very low,

Am I OK?

It turns out 98.6 degrees fahrenheit isn't really the

ideal or normal body temperature.

There's really no such thing.

But temperature can still tell us a lot about our health.

And about the spread of COVID-19.

(temperature machines beeping)

The number 98.6 mostly came from 19th century German

researcher Carl Reinhold August Wunderlich.

He claims to catch the numbers of more than a million

in temperature readings to thousands of patients.

And he arrived at the number of 98.6.

That number has stuck around ever since.

But person to person

it's kinda meaningless.

We asked our co workers to take their own readings

and this is what normal temperature looks like for us.

- 95.83.

- 96.7 which seems low.

- I'm a cold,

cold man.

- Maybe [Inaudible]

I would have thought.

- It's fine.

I guess.

- Wunderlich himself knew that body temperature varied.

He recorded a healthy range from 97 and a quarter

to 99 and a half in his subjects.

Other studies have shown that temperature can differ

noticeably across age, gender, size and race.

And modern research points to a much lower number.

Around 98.

That squares with our very informal staff average.

We're around 97.5.

- You let her write the thermometers broken.

I don't know.

- What's more, you yourself don't have one body temperature

you have a range.

Our team all took their ratings at 10am.

But if you took yours a bunch over the course of a day,

you'll see it change.

Most people are coolest in the morning

and warmest in the early evening.

It's a reflection of your bodies natural rhythms,

your digestion, hormone production and cognition and more.

Here's what my temperature looks like

throughout the day.

- Other bodily cycles like ovulation can cause small

swings in temperature too and different parts of you

are different temperatures.

Under the tongue, armpit, forehead and rectal readings

are all likely to be unique.

Point is there are tons of variables.

We could be many temperatures all at once all the time

and still be perfectly healthy.

- But being sick is another story.

(theme sound)

So, I spoke with a couple of people who are connecting

some interesting dots

between temperature variation

and an illness like COVID-19.

When you get sick,

many of your bodies natural predictable rhythms

start to destabilize.

Your temperature might fluctuate more radically

and it might crank up above your natural range.

That's your body triggering a fever to make itself

less hospitable to viruses or bacteria.

In other words

your body temperature gets anomalous.

That's trouble for you,

but for people tracking COVID,

it's crucial data.

One effort is Kinsa.

A company that tracks the spread of infectious disease

using fevers.

Kinsa sells a smart thermometer that sends your

temperature back to the company every time you take it.

Kinsa says they have about a million thermometers

in circulation.

And with all that data,

they've built a real time health weather map.

It shows possible hot spots of COVID,

counties with more fever then flu season would explain.

- Let's take our real time signal

remove the expected value cold and flu.

What's left over is residual.

That residual is a typical, in this particular

analysis a typical fever clusters.

Things you would not expect.

What we found since that point is that

there's a very high correlation between our hot spots

and COVID-19 cases.

The work is not peer reviewed yet.

And some experts question how reliable it can be

with only a million thermometers.

Their user space could also be biased

by race or class or other factors.

But Kinsa still thinks it can tease out

some interesting trends,

like the effect of social distancing.

Here's their look at Miami-Dade County

in the middle of March.

In 9 days,

the percent of people with a fever

more than doubled.

And around the 17th and 18th,

they started implementing the closure bars.

So it starts going down.

- Other researchers are taking a different attack.

Looking for clues in body temperature that might

predict a fever before it starts.

- One study out of UCFS would collect temperature

and other health data from participants by using a

smart ring.

The rings can measure small changes in body temperature

every minute.

The question is, can tiny temperature rhythms

predict a brewing infections like COVID.

- And so we could pick up with great reliability

those ultranium rhythms, those within a day rhythms,

that there are frequency that tend to tell us about

how stagily your hormones passing along, how synchronized

are they inside of you.

- It's early days for the study

but once smart ring user

who tested positive for COVID has already shared

some interesting data.

- The temperature rhythms that I receive within the day

start to sort of destabilize and amplify

before they have a fever

right up to about 5 days beforehand.

The whole system would look like

it was sort of increasingly like a teeter totter

before they have a fever,

before they felt sick.

- Again that's just one patient.

But with enough data,

the team hopes to build an algorithm

that can sniff out COVID via rhythms like these.

- We will be publishing the findings

we will be putting out, you know,

competition or calls for [Inaudible]

get everybody in the room

let's get this as good as we could possibly get it.

This is really just

how big of a defense can we make.

How quickly to get this into service.

- In the coming months while we take our temperatures

every minute like maniacs

we're going to be hearing a lot more about the effort

to track and predict COVID-19.

Scientists will learn more about how the human body

regulates itself and respond to disease.

And along the way,

we might let go of some assumptions about what's normal

and healthy.

- Obsessing about 98.6 is really false precision right?

Everybody should have a nice daily rhythm of their

temperature.

The only time your temperature is constant is when your dead

and it's room temperature so

thinking about

the patterns of change rather than the absolute number

is much more important.

- Psst cat, go on.

Oh cat get outta there.

Cat [Inaudible]