Temperature tracking guide
Logging a Baby's Temperature, Including Where You Measured
Once a fever starts, the times and readings blur together within hours. You took it twice overnight and by morning neither the numbers nor the timings are clear. Yet the course of the fever is the first thing anyone asks about in a consulting room. A temperature log exists to preserve that course.
Last reviewed 2026-08-08 · A general record-keeping guide, not medical advice.
A number alone is half a record
"38.2" on its own supports no decision later, because it carries neither when nor where.
Every temperature entry needs three things:
- The time it was taken
- The site — ear, underarm, forehead, or rectal
- The reading
The site matters most. The same child at the same moment reads differently depending on where you measure.
Mixing sites destroys the trend
To see whether a fever is climbing or falling, you have to compare like with like. Alternate between ear and underarm and you cannot tell whether a change reflects the fever or the method.
Use one site where possible, and when you have to switch, record that you did.
What appears when medication sits alongside
A temperature log becomes most useful overlaid with doses.
| Time | Temp | Medication | | --- | --- | --- | | 21:00 | 38.6 (ear) | Antipyretic given | | 23:00 | 37.4 (ear) | — | | 02:30 | 38.9 (ear) | — |
Read together, this shows a drop about two hours after the dose and a return roughly five hours later. That is information clinicians ask about constantly.
Keeping medication records separately is covered in baby medication logs.
Mark when the fever began
The first question in most consultations is when the fever started — and it is surprisingly hard to answer. In the blur, last night and the night before merge.
Flagging the moment you first registered a fever means you can answer that immediately later.
When the log comes second
A record explains a course; it is never a reason to delay. In particular, contact a medical service straight away rather than updating your log if:
- Your baby is under three months old and has a fever
- Your baby becomes floppy, or is responding noticeably differently than usual
- There is a seizure, or breathing looks laboured
Deciding what constitutes an emergency is a clinician's job, not something to read out of a parent's records.
Frequently asked questions
- Readings differ by site. How should I record that?
- Record the site alongside the reading. Ear and underarm use different baselines, so mixing them makes the trend unreadable. Stick to one site where you can, and flag it clearly when you switch.
- What temperature counts as a fever?
- Thresholds depend on the measurement site and on your baby's age, with separate rules for infants under three months. Follow your clinician's guidance rather than judging the number yourself.
- Should medication go in the temperature log?
- Keeping them together helps. When the dose times overlay the temperature curve, you can see how long the effect lasted and when it climbed again.
- Should I take temperatures when my baby is well?
- There is no need to do it daily. Taking it a few times while your baby is healthy does give you a personal baseline to compare against later.
- What should I bring to an emergency department?
- When the fever started, the highest reading, and when and how much medication was given are the three most commonly asked. If it is in your log, you can simply show it.
Sources
Shared records instead of memory