I was going to suggest whether sending check-in messages to your mum during the day to remind her about keeping the dogs cool would help, then i realised she has them whilst you sleep! Silly me!
Does you mum know about your SI struggles? If so, is she someone you can call right now to vent it all out and get some reassurance that she cares and wants you to live? @Captain24
I know some people arent good with MH or SI though and that may not feel a safe option.
What was the word @Jynx used for you? Precious, i think it was?
Do you reckon your mum would be willing to always do the "palm on ground" test for heat before going for dog walks?
And i very much agree with you that a 40 degree day the paving will still be too hot even in the evening after the sun goes down for quite a while. Maybe she needs to give them a *midnight* walk if she can't resist at all. Or a 5am walk because thats the coolest time right, just before sunrise?
Its so hard when you dont feel you can safely entrust your pups to. I had a lot of these concerns with my now-ex when he wasnt coping/treating/recognising his depression. Although i knew they were safe for a day or two at least, my concerns were about fulltime care of them without me organising everything. Thankfully now he is coping better i am not worried and trust he can/would look after them without me.