Actually, for fever (as opposed to physical injury), the wet towel is an officially recommended useful thing to do (please note the difference between that and "remedy").
Source: at least 3 different pediatricians when my kids had virus-originated fevers. (NOTE: this is somewhat tongue in cheek, but is based on sound evidence as linked to below)
This serves 3 medical benefits:
Depending on the temperature of water, it cools down the person if it is below the skin temp. Source: NIH
By wetting down the face and then allowing the water to evaporate, it allows the person to cool down faster/better. Source: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/sweat.html
It removes eeky sweat generated when one has a fever. if nothing else, that makes you feel less unpleasant and thus has non-negligible contribution to well being.
Add an overall sense of being cared for, AND a calming effect of doing something helpful for a parent - both are important. Source: Managing childhood fever and pain – the comfort loop, Jacqui Clinch and Stephen Dale, Child and Adolescent Psychiatry and Mental Health
On the other hand, I found at least one study which contradicts this on some level.
to whit, the study showed
It improves the fever short term (1 hr). SUPPORT
Has no effect longer term (2+ hr). NO Support, but the claim didn't specify time period
Study showed correlation between bath and discomfort. See my opinion of that below.
The efficacy of tepid sponge bathing to reduce fever in young children.
Sharber J. College of Nursing, University of Arizona, Tucson 85721, USA.
Abstract : Tepid sponge baths distress febrile children, and their efficacy at reducing fever has not been established. This study compared fever reduction and with (1) acetaminophen alone and (2) acetaminophen plus a 15-minute tepid sponge bath. Twenty children, ages 5 to 68 months, who presented to the emergency department or urgent care center with fever of > or = 38.9 degrees C were randomized to receive (1) acetaminophen alone or (2) acetaminophen plus a 15-minute tepid sponge bath. All subjects received a 15-mg/kg dose of acetaminophen. Tympanic temperature was monitored every 30 minutes for 2 hours. Subjects were monitored for signs of discomfort (crying, shivering, goosebumps). Sponge-bathed subjects cooled faster during the first hour but there was no significant temperature difference between the groups over the 2-hour study period (P = .871). Subjects in the sponge bath group had significantly higher discomfort scores (P = .009).
Based on my own experience, the final conclusion of the study may plausibly be wrongly attributed (the child may be discomforted because they don't like sponge baths in the first place, especially when in fever and wants to be held still or not bothered) - once my kids were older and could consciously consent to it, the exhibited discomfort went from 50% of cases to 0%. The abstract didn't specify any details discomfort-wise, so i don't know if they bothered with adjusting for that effect.
Here's a second study showing the same results:
Comparative Effectiveness of Tepid Sponging and Antipyretic Drug Versus Only Antipyretic Drug in the Management of Fever Among Children: A Randomized Controlled Trial
S THOMAS, C VIJAYKUMAR, R NAIK, PD MOSES AND B ANTONISAMY; From the Department of Child Health Nursing, *Child Health Department and **Department of Biostatistics,
Christian Medical College, Vellore, India.
Results: The reduction of body temperature in the tepid
sponging and antipyretic drug group was significantly
faster than only antipyretic group; however, by the end of 2
hours both groups had reached the same degree of
temperature. The children in tepid sponging and
antipyretic drug had significantly higher discomfort than
only antipyretic group, but the discomfort was mostly mild.
Conclusion: Apart from the initial rapid temperature
reduction, addition of tepid sponging to antipyretic
administration does not offer any advantage in ultimate
reduction of temperature; moreover it may result in