UHT cream storage - temperature extremes I buy canned Anchor brand butter, which is sent by road unrefrigerated where afternoon temperatures are around 29C, sometimes higher. On one occasion I received a can that had melted and was no longer usable as butter (though fine for ghee or whatever). I understand butter melts around 32C.
The local supermarkets, which I guess are air conditioned to around 22C sell unrefrigerated canned butter, and refrigerated UHT cream.
According to Anchor
https://www.anchorfoodprofessionals.com/us/en/products/cream/anchor-chefs-heavy-cream.html
For best results:

The product can either be stored ambient between 68°F and 77° or refrigerated between 36°F and 39°F.
Keep out of direct sunlight.
Rotate the stock regularly.
Anchor™ Chef’s Heavy Cream has a 9-month shelf life.
For optimal results, once stored in either refrigeration or ambient the product is to remain in that environment pre- and post usage.

That's 25C, which is definitely cooler than I'd expect to receive good sent by road, which might be 28-29C. That's for the US.
For SE Asia however
the carton seems to say
keep refrigerated

whereas the website says
https://www.anchorfoodprofessionals.com/sg/en/products/cream/whipping-cream/anchor-whipping-cream.html

Store unopened packs out of direct sunlight. Once opened, keep chilled at 2°C to 4°C and serve within 3 days. Check and rotate stock regularly.
Anchor UHT Whipping Cream is stored at 2°C to 4°C after manufacture and during international transport.

which kinda suggests it doesn't need to be refrigerated.
Some references say that UHT cream should be refrigerated for 24 hours before usage, which is fine. The question is at what ambient temperature will the product be permanently damaged? Most sellers seem slightly happier about sending canned butter than UHT cream, but I'm not sure if that is anything fundamental about the product, in that it would make more sense to have a lower melting point about butter, which is solid, compared to cream, which is already liquid
I couldn't find any recent scientific literature on UHT cream, but I did find a bit on UHT milk.  And at least what's said about milk indicates that it should be fine being stored up to 37C.  This study says that shelf life is shortened above 30C, but that &quot;shortened&quot; still means 4-5 months.  And this one(pdf), from Sudan, found that a &quot;room temperature&quot; of 33C for UHT milk didn't hurt quality at all within 90 days.
However, that's milk.  What do we know about cream?
This old study suggests that UHT Cream has a significantly shorter shelf life than UHT Milk, and that it's a lot more affected by temperature.  In that study, you can see that flavor declines a lot faster at 18C than at 4C, and that separation of the cream happens at 18C in as little as 4 weeks.  While there's no data on storage at 30C, one would expect it to separate even sooner, maybe in as little as a week.  If you can get access to the Journal of Dairy Science, they may have more updated articles on UHT Cream shelf life.