[TELECOM Digest Editor's Note: Interesting you wrote about this today
> when the outside temperature here in Independence reached 106 degrees;
> the hottest for this year so far. My air-conditioning has been running
> almost continuously for the past two days. I do not know how I
> survived back in the 1950-60s when the places I worked did not have
> a/c nor did I have it at home until around 1968 or so. PAT]
It's warm and humid around here too, which is what prompted me to write the note.
I don't know how working people survived without air conditioning, especially 40 years ago when people had to wear much more clothing at work than they do now -- men had to wear suits and long sleeved shirts (albeit lightweight material), women full dresses. Today young women come to work dressed for the beach, pushing the envelope a little too much for most employers. Many men don't wear ties. I believe many years ago the workday started very early (6am) to beat heat. Also, older buildings had high ceilings and cross ventilation by design, plus awnings over windows to help. That might help the temperature, but high humidity? Again, I don't know how the many office workers in Washington DC during WW II survived; only a few buildings at that time had a/c.
I recall a photo of an old switchboard room in Texas where fans were directed at blocks of ice in pails in an attempt to reduce 100+ temperatures for the operators. While switchboard lamps and currents were tiny, collectively they did throw off some heat.
I presume relay operated telephone equipment was not affected by high heat or humidity (or cold for that matter). That is, relay parts wouldn't expand so much as to get out of alignment or timing (many telephone relays operated slowly by design). Likewise for motors that drove panel or SxS banks, and xbar switches and control logic relays.
Likewise, I wonder if relay controlled IBM tabulating/accounting machines, built before A/C, were sensitive to high heat. The last generation (1948) used very tiny precision built relays. Some machines used tubes which threw off heat.
[TELECOM Digest Editor's Note: When I worked at University of Chicago in the phone room we had overhead ceiling fans which would spin around every few feet up and down the room. They did not do much good, IMO. PAT]