Photo caption is Cym Valentine's Love. Looked it up...One parent is Cym Peter Pan (which is half ensifolium) So that one should, indeed, be "warmth tolerant" - not needing cool-down.
Couple of parents to look for in ancestry, parents or grandparents... Cym. Peter Pan and Cym. Golden Elf (both are Cym. ensifolium hybrids), seem to impart considerable warmth tolerance