Mermaids have some tips on how to manage in a heatwave with a binder. Because - guess what! - it's not a great idea to constrict your breathing! And I presume wearing a binder must increase the risk of heatstroke.
Mermaids suggests these tips will help avoid heatstroke/fainting while wearing a binder:
Don't wear black
Stay out of the sunlight
Avoid exercise
Only if you feel symptoms of heatstroke do they recommend you remove the binder:
'watch out for signs of heatstroke or heat exhaustion. If you think you have these symptoms, tell a friend so they can watch out for you. If you can, get to a place where you can remove your binder '
mermaidsuk.org.uk/news/summer-binder-safety-tips1293489163895963650
Why does Mermaids want to facilitate children risking their health? If a child or teenager feels that they have to conceal or alter their body to fit some idea of 'gender identity', it suggests they are in need of help to manage their feelings, emotions or mental health. They need support to ask why they might wish to risk their health to fit some imagined body ideal.
Not tips on how to mitigate the risks of wearing a binder.