The thermometer is perhaps the most used medical device in the world, and yet it’s one of the last to connect to a mobile device and an app.

New York-based Kinsa Health takes care of that problem with the first smartphone thermometer to be approved by the Food and Drug Administration (FDA).

The Kinsa Smart Thermometer works just how you’d think it would: A small plastic stick goes in the mouth (or under the arm or, uh, down below) while the other end fits into the phone’s headphone jack. The thermometer uses the smartphone’s display, power, and processor to determine a precise temperature reading. The device needs only about 10 seconds to arrive at an accurate temperature reading, Kinsa says.

Kinsa’s thermometer might be a hit with parents looking for a better way to get kids to sit still long enough to get their temperature taken.

kinsaInvestors seem to think so. Kinsa says it has raised $9.6 million in new venture funding from Kleiner Perkins Caufield & Byers (KPCB), FirstMark Capital, Andy Palmer, and others. Kinsa CEO Inder Singh said his company will use the new funds to scale up production of the thermometer, recruit top-tier talent, build awareness through marketing, and expand the product line.

With every high temperature reading, the Kinsa app (free, for Android and iOS) provides the user with contextual health information about what the reading might mean.

The Kinsa mobile app lets users create individual profiles for each member of a family; record and monitor fever, symptom, and illness history; report the progression of illnesses to physicians; and document any physical symptoms with photos.

Singh says users will soon be able to join groups of users, which might allow them to understand what is “going around” in their own social circles (schools, offices, neighborhoods, etc.).

This concept points toward what may be the next step for Kinsa Health. Singh says he would like to develop the company’s software platform to the point where it can collect health data from all sorts of connected health devices (including wearables, eventually) to provide insights on where the next epidemic may be developing, for example.

But for now, Singh said, Kinsa can go a long way with just the thermometer. “We’ve reimagined the world’s most common medical device, the thermometer, and given it the potential to improve the health of entire communities,” he says. “This is the first part of our bigger mission to create the first real-time map of human health using mobile technologies to track — and stop — the spread of illness.”

Thinking big on public health issues is nothing new to Singh. He was previously executive vice president of the Clinton Health Access Initiative (CHAI), which is part of the larger Clinton Foundation. At CHAI, Singh spent five years traveling through 35 developing nations, negotiating deals with drug companies that gave access to life-saving drugs and diagnostics to more than half a million children.

The Kinsa Smart Thermometer is available at Apple and CVS stores in the U.S. as well as online at Amazon,, and Kinsa’s website for $30.