It’s 8 AM and you’re gathering vitals for the unit. You grab your thermometer and reach for a resident’s armpit—you are performing an axillary temperature check, the safest and most common method for stable residents.
What is Axillary?
Axillary (AK-sih-LER-ee) is the medical term for “relating to the armpit.” The axilla is the hollow space located just under the shoulder joint where the arm connects to the torso. While it refers to the anatomy of the area, you will most often use this term when discussing temperature measurement, though it also applies to hygiene and skin checks in this region.
Why Axillary Temperature Matters in Your Daily Care
Taking an axillary temperature is the standard for many long-term care facilities because it is non-invasive, safe, and comfortable for the resident. It is less invasive than oral (especially if a resident is confused or has breathing difficulties) and much safer than rectal temps. Getting an accurate reading here is crucial because a fever is often the first sign of infection, like a UTI or pneumonia. If you mess up the technique, you might miss a crucial warning sign.
What You’ll See During Your Shift
You will encounter this daily during your vital signs rounds. You will see the thermometer probe placed high and tight in the armpit, usually requiring the resident to lower their arm to their side to hold it in place. You may also notice skin irritation or moisture in this area during baths, which requires diligent care to prevent breakdown.
“Mr. Henderson, I need to get your temperature. I’m going to place this thermometer in your axillary area—right here under your arm. Please keep your arm down snug against your side so we can get a good reading.”
Common Pitfall & Pro Tip
⚠️ Pitfall: Placing the thermometer on top of sweat or damp skin. Moisture acts as a coolant, causing a falsely low reading that might cause you to miss a fever.
Pro Tip: Always dry the axilla thoroughly with a washcloth or towel before placing the thermometer probe. Ensure the probe is placed high up into the center of the armpit (the apex) and have the resident cross their arm across their chest for the tightest seal.
Memory Aid for Axillary
Think: “Axilla = Accessory Armpit.”
Or simply remember: “A is for Armpit and Axilla.”
This reminds you exactly where the term points to on the body when you see it in care plans or hear it during shift report.
State Test Connection
This is a core skill in the Vital Signs section of the CNA state exam (Prometric/Pearson VUE). You will likely be tested on taking an axillary temperature and must demonstrate proper site cleaning, probe placement, and holding time to pass.
Related Care Concepts
Mastering the axillary check connects directly to vital signs and infection control. It also relates closely to perineal care and bathing, as keeping the axilla clean and dry is essential to preventing skin maceration and fungal infections in warm, moist body folds.
Quick Reference
✓ Key steps: Dry skin completely, place probe high in armpit center, arm tight to side ✓ When to report: Readings above 100.4°F (or facility specific protocol) ✓ Care reminders: • Wait for the thermometer to beep/signal before removing • Do not take axillary temp if the resident has an IV in that arm • Document the specific site used (e.g., “100.0°F axillary”) • Check the area for redness or skin breakdown during baths
Bottom line: A correctly taken axillary temperature gives the nurse the data they need to treat your resident quickly, keeping everyone safe and healthy.