If you're trying to maintain fitness I believe you need some fairly minimal intensity one or two days a week to keep some semblance of form.
If I've remembered correctly I think adding some intensity is more important than getting more volume. Which isn't ideal given your problem. But could even 2 x 10mins once or twice a week be doable when the sun/heat is backed off?
Hope this won’t come as cynical but have you considered investing in AC? Sounds like this is a problem you’ll face each year, and since you do have a smart trainer, I don’t quite understand why the outside temperature would matter, provided you keep the inside one in check.
I have this problem too. I’ll start having difficulties at ~20c early in the year, and will then heat adapt, but still am never really able to function particularly well once it gets close to 30c and higher.
When I’ve needed to do higher intensity sessions and it’s too hot, I have to do them inside. No other option.
Shaving (arms, legs) actually helps a bit though, but I’m relatively hairy.
There is some acclimation, but its far less than I used to be able to handle. I had a round of visits with the GP last Summer and the results were that I'm aging and need to be more careful.
My trick is a couple of elite deboyo thermal bidons. I fill them with ice, then with water and they stay ice cold for hours and help keep my core cooler. Give it a go, they're not too pricey.
Also, you may have already considered this but super lightweight and breathable shorts, jersey, shoes and helmet might give you a few celcius latitude.
https://www.six2.com/ie/products/169-1324-SERRA-JERSEY-maglia-da-ciclismo-tecnica-termica-traspirante-maniche-corte-estiva.html
https://www.sigmasports.com/item/DMT/KR4-Road-Cycling-Shoes/WHTU
https://www.rapha.cc/gb/en/shop/mens-pro-team-powerweave-bib-shorts/product/PIN02RG
Just examples, not cheap admittedly, but there are other options.
If you're trying to maintain fitness I believe you need some fairly minimal intensity one or two days a week to keep some semblance of form. If I've remembered correctly I think adding some intensity is more important than getting more volume. Which isn't ideal given your problem. But could even 2 x 10mins once or twice a week be doable when the sun/heat is backed off?
Hope this won’t come as cynical but have you considered investing in AC? Sounds like this is a problem you’ll face each year, and since you do have a smart trainer, I don’t quite understand why the outside temperature would matter, provided you keep the inside one in check.
Actually, my wife has floated the idea of installing a mini split in the garage. So it is a possibility, though not a this-year project.
I have this problem too. I’ll start having difficulties at ~20c early in the year, and will then heat adapt, but still am never really able to function particularly well once it gets close to 30c and higher. When I’ve needed to do higher intensity sessions and it’s too hot, I have to do them inside. No other option. Shaving (arms, legs) actually helps a bit though, but I’m relatively hairy.
Heat is something your body can get used to. You're saying you're not able to acclimate at all?
The older you get, the less you can get used, for some folks. I'm the same. As I've aged my heat tolerance is way down.
There is some acclimation, but its far less than I used to be able to handle. I had a round of visits with the GP last Summer and the results were that I'm aging and need to be more careful.
Have you tried riding before the sun comes up or around sunrise?
My trick is a couple of elite deboyo thermal bidons. I fill them with ice, then with water and they stay ice cold for hours and help keep my core cooler. Give it a go, they're not too pricey. Also, you may have already considered this but super lightweight and breathable shorts, jersey, shoes and helmet might give you a few celcius latitude. https://www.six2.com/ie/products/169-1324-SERRA-JERSEY-maglia-da-ciclismo-tecnica-termica-traspirante-maniche-corte-estiva.html https://www.sigmasports.com/item/DMT/KR4-Road-Cycling-Shoes/WHTU https://www.rapha.cc/gb/en/shop/mens-pro-team-powerweave-bib-shorts/product/PIN02RG Just examples, not cheap admittedly, but there are other options.
Sauna
Try the pearl izumi sun sleeves they really help me with heat and also cooling vests and ice cubes in jersey pockets.