I've wondered about this for a long time, and hopefully someone here has a reasonable answer. I'm a cell and molecular biologist, and much of my time at the bench is spent wearing (usually nitrile) gloves. I've noticed that if I wear them for longer than 10 or 15 minutes they start accumulating sweat. However, my hands aren't clammy or damp when I'm not wearing gloves, so my question is whether my hands are always sweating at approximately the same rate, and the impermeable barrier of the gloves just traps the moisture, or does the enclosed environment inside the gloves promote sweating? My hands don't seem particularly hot when I have the gloves on, and the gloves themselves are pretty thin, although they do have some insulating properties, as I can handle items taken from a -80°C more easily gloved than bare-handed. What causes this diaphoresis?
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3$\begingroup$ Skin produces a basal level of sweat all the time, so as far as makes sense to me, they simply prevent evaporation. $\endgroup$– ArmatusMay 29, 2013 at 18:03
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$\begingroup$ To the (potential) close-voters: This is not a medical question (I'm not asking for medical advice, I'm simply describing a phenotype). This isn't (or shouldn't be) primarily opinion-based, because I'm not asking for opinions, I'm asking if there is a clear, biological explanation for this. If you happen to disagree, please leave a comment and I'll try and clean up the wording. $\endgroup$– MattDMoDec 11, 2014 at 15:39
1 Answer
Hand sweating has been fairly well-studied, both because sweating from the hands is one of the main mechanisms of heat dissipation at higher temperatures and because there is a significant effect on palmar sweating by the autonomic nervous system (the main cause of hyperhydrosis of the palms).
Disregarding autonomic effects (stress response), the single most important determinant of hand and foot blood flow is the thermal status of the body core. Heat dissipation is more marked in the hands than feet, and remains so as temperature increases.
Studies have been done of palmar sweating in extremes of temperatures, palmar sweating changes with aging (decreases), palmar sweating in disease, etc. But what has not been studied is the effect of localized heat on sweating of the palms, which would be of interest to you if sweating was a result of the insulating capacity of the gloves.
What is known about palmar sweating is that it is an ongoing and important process in both genders, at all temperatures, and at all ages. The most reasonable assumption then, given the limits of the literature, is that your hands sweat continuously and steadily at a given temperature, and it is highly likely that you are noticing it when wearing gloves only because the vapor barrier caused by the gloves prohibits evaporation.
The roles of hands and feet in temperature regulation in hot and cold environments
OBSERVATIONS ON THE ACTIVITY OF SWEAT GLANDS WITH SPECIAL REFERENCE TO THE INFLUENCE OF AGEING
Why do I get sweaty palms?
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$\begingroup$ But then - If sweating reduces temperature, would the increased temperature not facilitate sweating? That was the reason for me not answering this, apparently, but actually not quite obvious question (+1 for the excellent answer btw :-) $\endgroup$– AliceD ♦Dec 11, 2014 at 3:50
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1$\begingroup$ @ChrisStronks - That's a real possibility! Palm sweating is a response to core temperature. Hand temperature isn't reflective of core temp (it varies much more), and there were no studies where the hands alone were warmed to measure it's impact on core temp or sweat production or evaporation was prevented. I have to guess, then. I think it's unlikely that the small heat gain from the hands would affect the core temperature, but I could be wrong. I wished I had found more on that (it was frustrating not to be able to say definitively). :-/ $\endgroup$ Dec 11, 2014 at 4:52
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$\begingroup$ @ChrisStronks Sweating does reduce the temperature - you are right. But the glove prevents evaporation and thereby the cooling effect. $\endgroup$– Chris ♦Dec 11, 2014 at 7:47
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$\begingroup$ @Chris - yes! And therefore without the evap-cooling effect (I thought) the hands would start to sweat more because of the local temperature increase (sorry I wasn't clear). But as (@)anongoodnurse indicates: it's core temperature that drives sweating so my reasoning isn't valid I guess :) Interesting question after all :-) $\endgroup$– AliceD ♦Dec 11, 2014 at 11:57
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1$\begingroup$ Thanks for the answer, I had kind of forgotten about this question. It's too bad there hasn't been any work done on local temps, because I suspect that's why this happens - the gloves are somewhat insulating and there's no opportunity for evaporation, therefore raising the local temperature and causing a positive feedback loop. I guess I'll have to read up more on sweating disorders, as I tend to be rather... shall we say... damp frequently, but that's OT for here unless I anonymize it :) $\endgroup$– MattDMoDec 11, 2014 at 15:48