Monday, March 08, 2004

Kelvin, Celsius, Rankine, Reaumur:

When they get wet, they're baaaad.

On reading a presentation about the recent heat wave in France that unfortunately killed many elderly people left without a/c or water, I came across this paper:

Steadman, R.G., 1979. The Assessment of Sultriness: Part I: A temperature-humidity index based on human physiology and clothing science. J. Applied Meteorol., 18, 861-873.

Sultriness? Physiology? Clothing Science? ...somewhere in the distance, Jessica Rabbit says: "I'm just drawn that way."

Despite the title, this is actually a pretty fundamental paper in that it lays out the scientific ideas behind the Heat Stress Index, or HSI. It's a rigorous approach to the concept that we all know: a 30°C temperature reading might be equal in London and Los Angeles, but it certainly won't feel the same to a human.

Not only because of humidity or wind, but because of things like "...and how many days has the mercury been this high?", and " this unseasonal or not?", and even the "...even if it were this hot in the country, I'd rather be there." factor.

Once you think about it for a while, I think you will agree that the first day over 30°C is a lot easier to tolerate than the tenth, that hot days when they are expected are just part of life, and that heat at the beach is much preferable to exactly the same conditions at the office.

I think this is one of the closest attempts I have seen at a scientific measure of the emotion surrounding a physical sensation.

Now if someone would just work on a good description of smell and taste, that would be progress. It always amazes me that we have a fairly good vocabulary for things like colours, but a pretty poor one when it comes to smell and taste. They seem to be so difficult to describe, so subjective. Perhaps it is because the things producing and detecting smell and taste are actually very complex compared to those for colour? Ophthalmologists in the blue corner, and otonarilaryngologists in the red, please. Ten rounds.

Like discomfort in heat, which depends on many factors.