Sauna and common colds: what a small early trial found
A small 1990 trial compared regular sauna use with no sauna over six months. The sauna group caught fewer colds, but the study is old, small and not randomized.
The short version
In 1990, researchers assigned 25 volunteers to regular sauna bathing and 25 to a control group, and tracked common colds for six months. The sauna group had significantly fewer cold episodes overall, especially in the last three months, when colds were roughly halved compared with the control group. Once someone caught a cold, it lasted about as long and felt about as severe in both groups. The trial was small, and the abstract does not describe random allocation, so the two groups may have differed from the start in ways that affected the result.
Keep in mind
A small, dated, non-randomized trial: 50 people in total, in two groups that were not described as randomly assigned. It suggests a question worth studying further, not an established way to avoid colds.
What they found
The sauna group had significantly fewer cold episodes than the control group over the six months, as reported by the authors. The difference was clearest in the last three months of the study, when the control group’s cold rate was roughly double the sauna group’s.
Once a cold started, its average duration and severity were similar in both groups. In the authors’ words, sauna bathing appeared to affect how often colds occurred, not how bad they were once they started.
The published abstract does not give the exact number of cold episodes in each group, only that the difference was statistically significant.
What this means for your practice
This is an old, small and interesting result, not proof that sauna sessions stop you from catching a cold. If you enjoy the sauna, this is a mild point in its favor, nothing more.
This does not establish a sauna routine to follow, and it is not a reason to skip care for a cold you already have.
Methods and limitations
What the researchers did
In 1990, researchers in Austria studied whether regular sauna bathing affects how often people catch a cold. Fifty volunteers took part: 25 used the sauna regularly, and 25 made up a control group that abstained from sauna or similar heat exposure.
The frequency, duration and severity of common colds were recorded for both groups over six months. The published abstract does not describe how people were assigned to a group, so this is treated as a non-randomized, controlled trial.
This is one of the earliest studies on sauna and infection risk, long before the much larger KIHD respiratory-disease study that came almost three decades later.
How much can this tell us?
This is a small, dated study: 50 people in total, from an era before today’s reporting standards for clinical trials. The lack of a described random allocation method is a real limitation: the two groups may have differed from the start in ways that affected their colds.
Diary-tracked cold episodes, over six months, in 50 adults, cannot settle the question on their own. The authors themselves concluded that sauna bathing “probably” reduces colds and that further study was needed. That is a fair summary, and it still applies.
A much larger, longer KIHD cohort study later reported fewer respiratory-disease diagnoses among frequent sauna users (see our respiratory-disease article), which points the same direction without being a replication of this specific trial or outcome.
What makes it useful
- An early, historically important question about sauna and infections
- Common colds tracked monthly for a full six months
- A comparison group that did not use the sauna
What limits it
- Very small: 25 people per group
- The abstract does not describe random allocation
- Self-reported, diary-based cold tracking
- From 1990; reporting standards were different then
Where this study fits
Where this study fits
We score claims, not single studies. This one is part of the evidence for:
Regular sauna means fewer colds. Early signal
Very low certaintyLarge effectIllness and death
Read the original
Ernst E, Pecho E, Wirz P, Saradeth T. Regular sauna bathing and the incidence of common colds. Ann Med. 1990;22(4):225-227.
DOI 10.3109/07853899009148930 · PubMed 2248758