Why Hasn't Cisco Cold-Proofed Flash's Costume Yet?
It has been known since almost the first episode of The Flash that intense cold is Barry Allen's Achilles' Heel. After all, cold is caused by a lack of molecular motion, and what good is a speedster if their molecules can't move? It was this logic that led Cisco Ramon to construct a Cold Gun that slowed molecular motion just in case Barry Allen ever became corrupted by his power. It's also what made career criminal Leonard Snart Barry Allen's most dangerous enemy after he acquired the Cold Gun and reinvented himself as the Arrowverse's Captain Cold.
Given that, it's a wonder that Cisco hasn't seen fit to try and alter Barry's costume in such a way as to better protect him from intense cold, particularly after he gave Barry a much-ballyhooed suit upgrade in season 4. The battle with Icicle in "The Icicle Cometh" revealed that, while Cisco may have come up with a way to have the suit inflate into a life-raft if Barry gets thrown into the water, he and Ryan Choi (the inventor of Barry Allen's season 5 costume) never saw fit to protect Barry from his greatest weakness. The Flash and XS are helpless after they knowingly run into an area where Icicle has lowered the temperature to near Absolute Zero. Even Icicle has to laugh at this, after the rest of Team Flash shows up and proves equally useless, saying "You people are not as smart as I thought."
What Is The Deal With Cicada's Wound?
In addition to unveiling the true origins of Killer Frost and Thomas Snow's other identity, "The Icicle Cometh" also revealed a good deal of information about Cicada. His real name was established as Orlin Gibbons and it was confirmed that his daughter, Grace, was injured on the night of The Enlightenment. It was also explained that Orlin has a deep hatred of metahumans, blaming them for his daughter being trapped in a coma.
The only question that remains regarding Cicada involves the wound in his shoulder and how it is connected to his dagger and his daughter. Previous episodes have seen Cicada refusing treatment for his open wound and this episode sees his wound getting worse even as he claims that he is becoming stronger with every metahuman he kills. If he is anything like his comic book counterpart, it's likely that Cicada may be hoping to use the power he is taking to heal his daughter, much as the comic book Cicada killed to gather the power need to resurrect his dead wife.
Why Is Doctor Ambres Helping Cicada?
Dr. Ambres was the pediatrician monitoring Grace Gibbons' condition in the final scene of "The Death of Vibe". That episode revealed that she knew about Cicada's wound, asking him if she could take a look at it to determine if it was getting better or worse. It was also hinted that she knew something about Orlin Gibbons' activities as Cicada, as she told him he had to give up what he was doing, though it was unclear if she meant being Cicada or not having his wound properly treated.
"The Icicle Cometh" confirmed that Dr. Ambres knew about Orlin Gibbons being Cicada and suggested that she shares his hatred of metahumans, complaining about how many patients she's treated because of "those metas out there." Still, it's quite a leap to go from complaining about people with superpowers making your job more difficult and abandoning the Hippocratic Oath to aid and abet a serial-killer. This suggests there is more to Dr. Ambres helping Cicada than simple hatred... but what is it?