Beds with sheets and mattresses are unsuitable for that kind of weather.

The traditional Indian Charpai (https://en.wikipedia.org/wiki/Charpai) is much more suited. It's like a hammock, but flat and stable on the ground, with great air circulation underneath the body. In hot weather one sleeps without a sheet on top.

Pointing fan at the bed will do nothing. When fans are moving the air of the same temperature around they will not cool any objects. If the ambient temperature is lower than than your body temperature, fans (and wind) help by moving warmed air away from your body and bringing the cooler one. Also fans (and wind) work because we perespirate. The less the humidity of the air around the body the easier it for sweat to evaporate so moving air helps by removing water molecules away and making it easier for new ones to evaporate.

All the time! Beds are always hotter here. Also the running water from the overhead tanks is so hot that it can burn your skin. With the India style bathrooms, you can imagine the horror.

It's hot here, but the humidity is almost 0%, which makes it bearable as compared to heat in cities like Chennai. Sweating is still efficient I would say, nights are certainly cooler in the area due to the sand dunes, which gets cooled quicker.

There is a point where the combination of heat and humidity means that humans can’t cool themselves adequately and die, even in the shade. This is happening more and more, and seems likely to start happening in places like eastern China and the US sooner than people think.

https://robertscribbler.com/tag/wet-bulb-temperatures-35-c/

Evaporating a given amount of water takes the same energy regardless of air temperature, but of course it'll evaporate faster, yes.

Low humidity makes it bearable, though you need to drink a lot.

Temperature usually fluctuates between 45-50 in peak summer days. That is the time when you cannot do much outside, but people do work. Most people have air coolers or air-conditioners at home and work.

Nights are relatively cooler, but heat waves can continue till late night as well.

I recall from my trip in 2008, doing camel safari from Jaisalmer (west india, Thar desert, amazing place). I counted plastic bottles and drank 6 litres of water just on the camel, and literally nothing came out of me. Sweat quickly evaporated in that low humidity environment. It was around 45-50 degrees outside, just sitting on that animal, slowly moving around.

At one point, I nearly collapsed from heat fatigue. It was just a sudden weakness, my head spinned a bit, I had to sit down and after few minutes I was a bit better. This was 3rd month backpacking in india, so one would expect at least slight adjustment. In cities, you just move from one AC place to the other and suffer through short periods outside of it (in fact heat subjectively gets much worse if you stay predominantly in AC place).

I can't imagine people doing any physical work under these conditions. There are some hard limits on human biology

Well, it's certainly tough. The heat wave makes it impossible to get outside. All you can do is stay indoors in air-conditioner.

Breathing per se should be fine. If you've ever been in a sauna, you'll know you can breathe air even when it's above the boiling point -- not for very long, to be sure, but that's got more to do with the extreme rate of sweating than your lungs. The lungs are always wet, which keeps them cool from evaporation.

People go to saunas where it is above 100 so 50 should not be that bad. Of course, I do not imagine anything productive can be done. OTOH, is it not close to working conditions in some mines? That sounds like hell.

have you ever been in a 120°C sauna? It's not that bad ... if you can leave after 15 minutes ;)