TSA Rules · Updated July 18, 2026
Can You Bring a Thermometer on a Plane?
Yes, unless it holds mercury. Digital and non-mercury thermometers fly in either bag. A mercury thermometer is only allowed in checked bags, in a protective case.
The rules
Carry-on essentials
Move through the airport fast and keep everything in its place from gate to gate.
Every option, one look
| Thermometer type | Carry-on | Checked | The rule |
|---|---|---|---|
| Digital thermometer | Yes | Yes | No restrictions |
| Forehead or ear (infrared) | Yes | Yes | Allowed anywhere |
| Mercury thermometer | No | Yes | Checked only, in a protective case |
| Meat or candy thermometer | Yes | Yes | Allowed; no probe-length limit |
The official word
Straight from TSA
“A mercury thermometer is permitted in checked baggage when packed in a protective case. Digital thermometers are allowed in carry-on and checked bags.”
TSA, What Can I Bring · verified July 2026
Before the checkpoint
Three calls that matter
Digital, infrared, and kitchen thermometers all fly freely. Only liquid mercury triggers restrictions.
If you must fly with a mercury thermometer, it goes in checked baggage inside a hard protective case.
A cheap digital thermometer avoids the whole question and reads faster anyway.
FAQ
Quick answers
Can you bring a thermometer on a plane?
Are mercury thermometers allowed on planes?
Can you bring a meat or candy thermometer in carry-on?
Is a forehead or ear thermometer allowed?
Sources: TSA: What Can I Bring · Reviewed July 2026