You gave a big clue with cold sensitivity. Your brother, just like Ehut wrote about in February, is getting FOLFOX. If your brother is far enough out from surgery that he is completely healed, he may also be getting Avastin, not a chemo drug, but a monoclonal antibody designed to cut off blood supply to the tumors. Before the chemo infusion, he is probably also getting an infusion of several antinausea meds; one of those may be a steroid (noticeable by flushed cheeks on day 2, possible difficulty in sleeping while the steroid is in his system, followed by a drop in energy when the steroid is gone). Some of do poorly with steroids, so that we joke here about having "'roid rage," a phenomenon that isn't necessarily rage, but certainly increased moodiness. (Just FYI.)
It is good that he tolerated the first round well, but very likely, each round will get a little harder, mainly for fatigue. My 3 big rules for chemo are:
Rest whenever you feel like it, even if you never, ever, needed a nap before
Exercise, even walking, if good for you, if at all possible, and if you don't feel like it, try at least a little before giving up
DRINK FLUIDS, even if you don't feel like it. Getting IV fluids (even bags of chemo) bags you want to pee. It's easy to pee more than you take in when you start feeling crummy. Getting dehydrated makes any chemo side effects worse.
Your brother will have his blood counts checked before every round of chemo. Expect WBC (white blood cells) especially, but also RBC to take a hit. The onc may ask your brother to come in for shots to build up his WBC, because lowered white count makes a patient more prone to infections. It is also not uncommon sometime in the FOLFOX regimen to have to delay a round or two because of lowered counts. Don't panic if that happens.
Just as others wrote earlier, the big goal is liver resection. I suspect the onc wants to start with just 4 rounds of FOLFOX, then do a scan to judge for effectiveness. If there has not been shrinkage, the onc may want to continue on FOLFOX for a while longer, or switch to another chemo. Best case would be enough shrinkage so that your brother is ready for a resection at that point. He would then continue with additional FOLFOX after healing from the liver surgery.
You seemed very concerned in an earlier post that the liver resection wasn't scheduled right away. Resectability of the liver depends on number, size, and location of the tumors. When I met my liver surgeon before I started chemo, he said resection was technically possible right away, but he always wanted to see the effectiveness of chemo first. After liver resection, "mop up" chemo is required to try to get any cancer cells still in the blood; or in the organs, but too small an agglomeration to show up on a scan. Having some chemo first tells the docs which chemo has the best chance of being effective as "mop up."
Hope this helps.
Best wishes to you and your brother,
May 06 Stage IV CC: liver,ovarian mets
Oct 07 inoperable lung mets
Feb 08 - Apr'12 chemo
allergic to oxaliplatin, irinotecan
Aug '12-Feb'14 Genentech PD-L1/Avastin trial
Mar '14 -radiation to largest lung nodule
still recovering; looking at trials again