I had some yeast shipped during that massive 100+ heat wave last summer. Two different packs. One was DOA, but the other survived with a starter.
Make a starter and you'll be ok. But my rule after the experience above, I do not order liquid yeast. Local purchase only. Dry yeast is another story.
Up Next: Spiced Winter Warmer, Brett. C. Old Ale
Primary: Best Bitter, English IPA
Secondary: Sour Stout, Wild Bitter
Polypinned: English Summer Ale, Coniston Bluebird Bitter Clone v1.5
Bottled: Sticke Altbier, Doppelsticke Altbier, Weizenbock, Berliner Weisse, Spruce Brown Ale, Arrogant Bastard Clone
Bottled for the long haul: Brett B. Tripel, Quadrupel, Tripel, Brett C. Oaked English Barleywine, Lamebic