Thermometer

It measures the temperature of the room you’re in. It’s the tool for finding Freezing Temperatures evidence.

How it works

Sound on

A simulation made by Phasmopedia with the game’s numbers. The sounds are recreated: they aren’t the game’s.

All three tiers	Tier IVintage wall thermometer	Tier IIInfrared thermometer	Tier IIIAir thermometer
Unlocks at	From the start	Level 27	Level 65
How it reads	On its own, always	While holding Use	While holding Use
Sample speed	0.33 °C per second	Every 2.5 s	Every 1.5 s
Maximum error	+3 °C	+3 °C	+2 °C
Freezing when it reads	Below 0 °C	Below 1 °C	Below 1 °C
Electronic	No	Yes	Yes

Tier I · Vintage wall thermometer
A wall thermometer with red alcohol, with °C on the left and °F on the right. It’s passive: it always shows the temperature of the last room you carried it in, but the liquid rises or falls slowly, 0.33 °C per second. It isn’t electronic, so it doesn’t draw the ghost to you during a hunt.
Tier II · Infrared thermometer
A digital infrared thermometer, like the ones doctors use. Turn it on and hold the Use button: it gives a reading of the room you’re in every 2.5 s. It’s fast, but it can read up to 3 °C too high.
Tier III · Air thermometer
A modern air thermometer that works just like the Tier II one. It gives a reading every 1.5 s and it’s the most accurate: at most 2 °C too high.

Take it to the room where you think the ghost is. With Tier I, just look at it and wait for the liquid to settle; with Tier II and III, turn it on and hold the Use button.
Every ghost cools down the room it’s in, whether or not it has the evidence: the coldest room is usually where the ghost is.
You can carry Tier I during a hunt without giving yourself away, because it isn’t electronic; Tier II and III are.

It only counts as evidence if it reads below 1 °C (exactly 1 °C doesn’t count).
With Tier I, wait for it to drop below 0 °C: between 5 and 0 °C it has fewer marks and it’s easy to misread.
Without the evidence, the ghost cools the room down to 1 °C; with it, down to −10 °C.
The error always goes up (up to +3 °C, or +2 °C with Tier III): if it already reads below 1 °C, the real temperature is the same or lower.

Seeing your freezing breath: since version 0.9.0 it no longer means Freezing Temperatures.
An airball ghost event, a ball of mist that looks like breath and moves toward a player.
A low temperature that doesn’t get below 1 °C, even if it’s below the weather’s temperature: it tells you the ghost is or was there, but it isn’t the evidence.

Turn off the fuse box at the start: rooms cool down faster. If it’s snowing, you can see Freezing Temperatures in about 2 minutes, as long as the ghost stays in its room.
The cold takes a while to go away: several rooms can be cold at once, and a freezing room doesn’t guarantee the ghost is still there or that it’s the ghost room.
Below the weather’s temperature, the room cools at a third of the speed: be patient before ruling it out.
If you pick a thermometer up off the floor, turn it off and on or change rooms before reading it: that cuts down on bad readings.

The Tier III one is actually a thermo-hygrometer, which also measures humidity; it’s based on the THS-224-612 model.
Its screen says “EMS 0.95,” an emissivity setting that only infrared thermometers like the Tier II one use.

Data from the article “Thermometer” on the Phasmophobia Wiki (CC BY-SA 3.0).