Hey everyone,
How surreal, I have been writing my PhD chapter about extreme heat in Tokyo, only to be presented with extreme heat right here in the (southern) UK. We are having a wild week my friends, it’s 34 degrees in London as I write this and may even get up to the high 30s in the next few days. Humidity is high (dew point 22 for the weather nerds) and it kinda feels like Tokyo. It’s stickyyy. Mushi-atsui in Tokyo speak, or just aatsu- (abrupt cutoff for dramatic effect) if you’re short on time.
The saving grace is the nights are still cool. In my eyes at least. Give me those cross breezes with the windows wide open! Yum. The Met Office, meanwhile, calls nights over 20 “tropical”. The JMA with 30+ nights would like a word… But it’s different in Tokyo, you guys have air con. We are still in denial about our newfound climate and none of our buildings are made for it. Some people live in tower blocks with no functioning windows.
We had a crazy storm last night too. I was dreaming restlessly about storms and woke up at 3:27am to the real thing, the sound of a gigantic CCRACKKK in the sky, so close it felt like it had hit something nearby (I live on top of a hill). And torrential rain cascading in curtains from above and rushing down the street. The sky was alight with flashes of lightning almost non-stop for three hours or more if I believe the reports, I’m not sure myself, I thankfully fell asleep again once the sun had risen and it felt less scary. The last time I saw a storm like that was in Tokyo, when “once in a generation rain” fell just as I was trying to get home on the train. I suspect both of them were “guerilla thunderstorms” formed by updrafts of hot air. (Here, have a spot-the-difference:)
london june 2026
tokyo july 2025
Here are some excerpts from what I’ve been writing:
When you’re out in it, the heat at the height of a Tokyo summer is all-encompassing – radiating from every angle, even if you have a UV-blocking parasol shading you from the worst of the sunlight. The air is thick with humidity and the cloying smell of sweat and fumes and mould. Avoiding sweat is an impossible task; even if you walk slowly, or wear breathable clothes, it just happens no matter what you do, and then your clothes stick to your body, losing any sense of breeziness. You feel lethargic like your thoughts are slowing down, and even basic things like walking around or taking stairs leave you out of breath. The sun is so strong, hot and bright – not a warm glow but a heat laser bearing down from above.
25th July was over 35°C for the first time in a few weeks, and the news was covering the effects on the whole country from the dangerously hot weather, interviewing people from all over the place. Some were stressed, but others were taking the heat in their stride. While a harried farmer described how his onion crop was wilting in the heat, a red-face ojisan (uncle-aged man) at a beer festival kicked back and exclaimed “well… time for another beer!” with an unbothered chuckle. It felt like the summer had really kicked up a notch, from hot but relatively comfortable to the kind of heat that becomes difficult to bear - mostly because of the increase in temperature, but also an increase in humidity, subtle but perceptible on the skin.
At the beginning of August, temperatures peaked even higher at 37°C, and remained high for an unbearable few weeks. After months of intensifying heat, each step hotter and sweatier and heavier than the last, a further escalation is difficult to put into words. Each crank of the temperature dial brings a new embodied experience. It is only after the heat rises – again – that what has gone before feels “cool” in comparison, something to long for when at the time it was a test of endurance in and of itself. By this point in the summer it was sensible to avoid spending a lot of time outside, although even these kinds of temperatures are somewhat manageable for short walks out of the sun. My usual walk to the metro along the main road was mercifully in the shade, thanks to the shadows of buildings and ginkgo trees, but there was a sense of the heat infrastructure beginning to creak under the strain. Writing fieldnotes from a café one afternoon, it was baking even with the AC on, the sun shining relentlessly through the bank of windows at the front of the building. That same day, the all time temperature record had been broken twice – the hottest day ever in Japan by a huge margin of around 0.7°C. It was still hot even on the way home after nightfall, 32°C as I trudged up the hill to the sharehouse. The air felt stuffy, humid, close. My trousers clung to my skin, soaked with sweat even though they were loose-fitting, supposedly breezy linen – changing out of them as soon as I got home had become a nightly ritual at this point, my room feeling relatively cool even at the 28°C setting I left it at when leaving the house each morning in an attempt to save electricity.
Practically though, all of this writing about heat means I have a good idea of how to deal with it. Do you want some tips? Here goes:
Obviously, stay out of the sun when it’s really hot. It’s easy to get heatstroke. If you have to go out, shade your skin from the sun using an umbrella, hat, long (loose!) trousers or sleeves, etc. Fans work to stay cool as long as it’s under 35. Wear SPF. Etc etc you know this already!
To cool down if you think you already or nearly have heatstroke (you feel headachey, dizzy, etc), use ice or cold water. Otherwise try not to cool your skin too much because that makes your body less able to deal with heat (when it’s hot, your body pushes blood to the surface so the wind or evaporating sweat can cool it down, if you make it cold, that blood will disappear away and you won’t cool yourself as effectively)
To maintain a cool house without AC, only open your windows when it’s cooler outside than in. During the day, keep them shut and keep sun off your windows if you can, otherwise shut the curtains/blinds. During the evening and night, open allllll the windows wide and try to get a cross breeze going. You can repeatedly open and close internal doors to get a breeze if there’s no wind outside. Practical UK tips here: https://heatwavetoolkit.com/
To prepare for the heat before it happens, you need to train your body to deal with it. It’s no use being cold all the time, then hot weather will be even more of a shock. As long as you’re not at risk of overheating, take hot showers and baths in the evening during summer rather than cold, then let your body naturally cool itself down in a cool room before you go to sleep. As a bonus, you’ll feel nicely sleepy. Also, take walks outside in the heat within your tolerance levels. You want to work up a gentle sweat but not overheat. Try walking one stop further than you usually would when catching the tube, train or bus.
Take electrolytes as well as drinking water, to replace the minerals you lose in sweat. If you drink water alone and drink too much of it, you’ll feel crap. You can buy electrolytes in supermarkets in the form of dissolvable tablets. In Japan they have them in edible tablet form which are much easier and less annoying to get down you than a whole drink, so try googling “chewable electrolyte tablets”.
Most importantly, embrace the swamp goblin feeling. If you make it a ✨vibe✨ it’ll feel more fun. Promise.
Good luck friends!
Stella x