A chemo cap isn't the same as a winter hat. Of course, sometimes these hats WILL be worn outside in cooler temperatures, so they CAN be warm, but often they are worn inside and really just need to fit well and be soft.
When choosing a yarn for a chemo cap, think about the recipient. Does this person live in a warmer temperature? Is the house air conditioned (could be cool) or not (could be hot)? Think about the care of the yarn, also. A lot of people don't wash their winter hats much (maybe they should!) but someone who is wearing a hat 24 hours a day will certainly want to wash it often. Don't choose a yarn that is too difficult to care for - a machine washable option is a nice benefit for someone who is feeling pretty awful. Having to hand wash a hat - as easy as that sounds - may actually be a pretty tall request for someone going through chemotherapy. Some yarns that call for hand washing may be able to be machine washed on gently in a mesh bag. Test your yarn first, or ask us for our opinion.
In terms of patterns, you may think that any old hat pattern - made in a soft yarn - will work. This isn't necessarily true. Having just helped someone very dear to me shave her head during chemotherapy, made me realize that a head with hair is not the same size as a head without hair. Go a little smaller.
Here's one option for a quick chemo cap that is very soft. We chose Berroco Marmot - a 100% nylon yarn that's available in beautifully rich colors. This hat measures 19.5" (circumference) by 7.5" tall. It does stretch a bit and there was some yarn leftover if you want to add a few stitches or rows. Just decrease to 60 stitches before your first round of decreases to make it work out. (Also, we feel that a gentle wash (mesh bag) would be fine. It will air dry pretty quickly too.)
This hat is a perfect indoor hat as it's amazingly soft. It could also be worn outside in some climates.
1 skein Berroco Marmot
Cast on 60 stitches. Place a marker at beginning of round. Knit every round until work measures 6” from cast on, ending at the marker.
Round 1: (k8, k2tog) around (54 sts)
Rounds 2, 4, 6, 8, 10: knit all stitches
Round 3: (k7, k2tog) around (48 sts)
Round 5: (k6, k2tog) around (42 sts)
Round 7: (k5, k2tog) around (36 sts)
Round 9: (k4, k2tog) around (30 sts)
Round 11: (k3, k2tog) around (24 sts)
Round 12: (k2, k2tog) around (18 sts)
Round 13: (k1, k2tog) around (12 sts)
Round 14: ( k2tog) around (6 sts)
Cut yarn leaving a 9" tail. Thread through the remaining stitches, draw up tights and secure. Weave in all ends.
We're working on another hat in a soft pima cotton blend and we'll post that when we've finished it.