From my Substack diary of Wednesday, 24th. June 2026

Yesterday’s record temperatures will be overtaken today as new records for June will be set. By late afternoon yesterday I was beginning to find it difficult to cope with the heat: I could feel the stress my body, and in particular my heart, was going through in order to maintain a core temperature of 37 degrees celsius. How will I fare today?

No cappuccino for me this morning. Instead I made myself an iced latte, although I think I overdid it with the hazelnut syrup. It is cool rather than cold, but pleasant nevertheless. I opened doors and windows (only those in the shade of course) at 0530 this morning, as usual when these weather conditions occur. But I knew the benefit from so doing diminishes over time, so the cooling effect would be reduced compared with yesterday. Sure enough, it was 21 degrees outside at that time and, at 10 o’clock as I am writing this, the outside temperature has already climbed to 28 degrees.

Getting out of bed so early in order to maximise coolth does, of course, result in broken sleep, but my sleep analyser tells me I was able to get some deep and even REM sleep after I returned to bed. I still feel tired – sleep tired. I suspect that, if yesterday is anything to go by ‘sleep tired’, which mainly affects the head and eyes, will be replaced with ‘heat tired’, which affects pretty much the whole body but particularly the muscles.

As ambient temperature increases the heart must work harder to maintain a healthy core temperature. Humidity has an effect also, and at the moment the humidity outside and inside is about 68 per cent, which is high – and not helping. It occurs to me that I could do with a dehumidifier, which would not only benefit the building fabric but also my health and comfort. There is of course a trade-off that would not be easy to manage, between having the dehumidifier on and windows and doors open. Reduced humidity or increased coolth? As for the heat, there is nothing much I can do over and above the ‘free’ measures I already take. Don’t even get me started on air conditioning!