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How to use an infrared thermometer

Updated: October 2026

You have the thermometer in your hand, or it is in the basket, and the laser dot looks as if it were measuring a pinprick. It is not. How to use an infrared thermometer depends on which instrument you bought: a forehead unit held close to dry skin, or a surface gun whose patch grows as you step back. The Products Compared editorial team took the distances and the warnings from the amazon.co.uk listings filed on 15 October 2026, and the optics from public guidance. There was no laboratory test. If you buy through our Amazon links, a qualifying purchase can earn us a commission at no extra cost to you. Which model belongs to which job is the [infrared thermometer comparison](/hub/climate-measuring/infrared-thermometer). This page is the procedure only.

You have the thermometer in your hand, or it is in the basket, and the laser dot looks as if it were measuring a pinprick. It is not.

Our top picks

ERICKHILL ERICKHILL ROOK600C, −50 °C to 600 °C

Best overall

ERICKHILL ERICKHILL ROOK600C, −50 °C to 600 °C
8.6/10about £14.99
View offer
ANMEATE ANMEATE FC-IR202 forehead thermometer

Alternative

ANMEATE ANMEATE FC-IR202 forehead thermometer
7.7/10about £15.99
View offer
G4GADGET G4GADGET forehead and surface thermometer

Best value

G4GADGET G4GADGET forehead and surface thermometer
6.8/10about £7.78
View offer
On this page
  1. 1.The laser shows where you aimed, not the whole patch
  2. 2.A forehead reading is a short hold on dry skin
  3. 3.A surface gun needs a clear patch and the right emissivity
  4. 4.Do not stare into the beam

The laser shows where you aimed, not the whole patch

The dot marks the centre of a patch. Fluke’s guidance puts it that way: the laser is an aiming aid, and the spot grows as you step back. Most guns here state 12:1, so at 12 cm the patch is about 1 cm across and at 36 cm it is about 3 cm. A narrow pipe from a metre away is mostly the wall beside it. Stand closer when the target is small. The MOONASCEND states 50:1, so the same retreat makes a smaller patch. The Soonkoda states no ratio. Do not borrow 12:1 from the Eventek, and do not apply the 12 cm example to a forehead. A gun from a cold car needs a moment before the first number. Choosing the ratio is the buying guide.

A forehead reading is a short hold on dry skin

A forehead unit is not held like a pistol. The only hold printed here is on the ANMEATE FC-IR202: less than 3 cm from the centre of the forehead, probe perpendicular, skin free of sweat, hair or dirt, and at least 10 minutes after cleaning. Do not copy that distance onto the OxiPro ear mode or the Thermobio, which do not print it. The G4GADGET title says gun. The file states no laser class and no 12:1 ratio. Treat it as a forehead unit, not an oven pistol. Sweat and hair sit between the sensor and the skin. The ANMEATE green, yellow and red backlight is an alert, not a diagnosis. For a child under five, use the NHS page: a digital thermometer in the armpit. If you are still unsure the device is for a person, that fork is the forehead thermometer or temperature gun page.
ERICKHILL ERICKHILL ROOK600C, −50 °C to 600 °C

Testsieger

ERICKHILL ERICKHILL ROOK600C, −50 °C to 600 °C
8.6/10about £14.99
View offer

A surface gun needs a clear patch and the right emissivity

Point at a surface you can see. If steam or dust crosses the line, Fluke’s advice is to get as close as is safe. Smoke off a stone becomes part of the number if you shoot through it. The ABOHU bullets say to keep vapour off the sensor and to use an angle on water or oil. The surface of the water is not the middle of the pot. Fixed 0.95, on both ABOHU guns, suits paint and a dull stone. Shiny metal under-reads. Eventek, ERICKHILL and the ThermoPro bullet move from 0.1 to 1.0. Soonkoda and MOONASCEND state 0.1 to 0.99. If you cannot change it, black tape on the spot is the workaround UK reviews of the ThermoPro describe for chrome or copper. The MUFASHA does not name emissivity. A stone number is still a surface. It does not show the centre of the food. That probe limit is the infrared thermometer for cooking page.

Do not stare into the beam

Do not look into the laser. UKHSA says Class 2 visible lasers are unlikely to injure in a brief exposure and are hazardous if you stare. Only the ERICKHILL ROOK600C states Class 2, and its bullet says not to aim at eyes. Every other gun leaves the class unstated. Unstated is not a licence to be casual, and it is not a safety grade you can invent. The Soonkoda and the Eventek can switch the pointer off. That removes the dot, not the sensor. Stop when the question has left the patch. A stone reading is not proof the food is cooked.

Common questions

Is the laser dot the area you are measuring?
No. The dot is the aim point at the centre of a larger patch. If the target is smaller than that patch, you are averaging in whatever sits around it. Body thermometers in this set do not use the 12:1 sum.
How close should a forehead thermometer be?
Only the ANMEATE FC-IR202 prints a hold: under 3 cm, probe perpendicular, on skin free of sweat, hair or dirt, and at least 10 minutes after cleaning. Do not copy that distance onto the OxiPro ear mode or the Thermobio.
Why does a shiny pan read low?
At a fixed 0.95, bare shiny metal reflects heat from the room and under-reads the pan. Adjust emissivity if the gun allows 0.1 to 1.0, as the Eventek, ERICKHILL and ThermoPro bullet do, or put black tape on the spot. Both ABOHU guns are fixed at 0.95, so tape is the option those listings leave you.
What should you do if steam or dust is in the way?
Move closer, only as close as is safe, so the sensor is not looking through the cloud. Vapour or smoke becomes part of the number if you shoot through it. The reading is still the surface you can see.
Can you use the same steps on a baby and on a pizza stone?
No. A forehead reading is a short hold on dry skin. A stone is a surface temperature, and the patch grows as you step back. The NHS method for a child under five is a digital thermometer in the armpit.
Is it safe to look into the laser?
Do not stare into the beam. UKHSA says a Class 2 visible laser is unlikely to injure in a brief exposure and is hazardous if you look into it on purpose. Only the ERICKHILL states Class 2. The other guns do not state a class. Unstated is not the same as harmless.

Related pages

Thermometer

Infrared thermometer

Best infrared thermometer for a forehead or a stone

Infrared thermometer buying guide: job, then range

Infrared thermometer for cooking: surface, not centre

Forehead thermometer or temperature gun: not one tool

Sources

Public UK sources used for this comparison. Listing prices, stars and review counts are from amazon.co.uk on 15 October 2026.

  1. MHRA — infrared thermometers: caution in use (retrieved 15 October 2026)
  2. MHRA — temperature-screening guidance (retrieved 15 October 2026)
  3. NHS — how to take a baby's temperature (retrieved 15 October 2026)
  4. NICE NG143 — recommendations for under-5s (retrieved 15 October 2026)
  5. Food Standards Agency — cooking your food (retrieved 15 October 2026)
  6. FSA — Safer Food, Better Business: Prove it (retrieved 15 October 2026)
  7. UKHSA — laser radiation safety advice (retrieved 15 October 2026)
  8. Which? — best digital thermometers 2026 (retrieved 15 October 2026)