Hot Weather

July has been a challenging month. My youngest daughter recently started attending day care, and the poor girl has caught four different illnesses since. People often say that young kids are out sick during the first month of day care due to exposure to new germs, and this proves to be true in our case. One or all of my wife, daughters, and I have been sick throughout the month.

As with much of the world, Japan has had warmer weather than usual this summer. It is currently 35 degrees C (95 degrees F) where I live, which widely is considered “hot” here. The term “hot” is subjective. Personally, I consider it to be “hot” when all of the following three conditions are met:

• The temperature is above average body temperature (37 degrees C / 98.6 degrees F).
• The ground heats up, so that you are heated from above as well as below.
• Any wind/breeze feels hot/uncomfortable, not cool/refreshing.

Where I live, not a single one of those conditions has been met so far this year. I have pretty good heat tolerance, and I still work and sleep without use of air conditioning.

Of the above conditions, temperature seems the most objective, but I am not so sure after recently reading Kim Stanley Robinson’s The Ministry for the Future, a “climate fiction” novel. The novel uses wet-bulb temperature (WBT). I was initially really puzzled that people were dying at 32 degrees C, but I then read on Wikipedia that it is equivalent to a heat index of 55 degrees C (130 degrees F). Perhaps I should rephrase the first condition to use “heat index” and not “temperature.”

The thermometer on the desk where I sit currently reads 30.1 degrees C (86 degrees F), with humidity at 75%. According to the chart on Wikipedia, that gives a heat index of 36 degrees C (97 degrees F). The temperature at my desk rarely reaches 31 degrees C, but the humidity sometimes gets up to 95%. That corresponds to a heat index of 42 degrees C (108 degrees F)!

It is probably worthwhile to note that I do not write this as a boast. People are different, and heat/cold tolerance is highly dependent on one’s experiences. A person is not “weak” just because they have a different heat/cold tolerance.