I wrote a post all about halo wearing back in March. It answers many of the questions asked about halos and what to expect.
I'd just like to add a few comments now on the differences between wearing a halo in the winter and the summer. Lucy had her last halo fitted from early December until late March. It was very cold but the vest is sheepskin lined so it kept her body warm. Unfortunately the sheepskin vest does not cover all of the body. The head and neck are exposed and because of the nature of the halo it is very difficult to cover these areas up. We did manage to thread a woollen scarf through the bars of the halo on really cold days which helped to keep her neck warm. There is no way of covering the head though, hats are out of the question. You can use an umbrella in the rain, but we found that the halo would keep getting caught on the spokes. We tried one of those dome shaped umbrellas but it wasn't much better. You are not supposed to get the halo wet so we found the easiest way to do this was not to go out if it was raining.
The halo vest does not cover the tummy and it is difficult to get clothing over the top. We managed to dress Lucy in a stappy vest under a shirt or button through cardigan a couple of sizes bigger than her regular size. Even then it was not possible to do more than two or three of the bottom buttons up and often the shoulders where uncovered apart from the halo vest. We found a big coat she could wear, but again couldn't do it all the way up for maximum coverage in the cold weather.
Apart from not getting the halo wet, it's also advisable not to go out when it's too cold as the points that enter the skull can get very cold and cause the wearer pain. This only happened to Lucy once, we did try to avoid taking her out when it was too cold.
When Lucy had the halo put on a second time it was in June. We have since had some really warm and sunny weather. So, no worries about covering her up and it hasn't rained much here either. It's not all good news though. We've found that Lucy has more headaches on sunny days. We are not sure if the halo is the cause, but she didn't really have so many headaches before it was applied. Also, the sheepskin vest is very warm. We've only been dressing her in her strappy vests, but she's still too hot and itchy all the time. It's even worse at night time when she's trying to sleep. She is just too hot.
We have had to be careful that she hasn't spent too much time in the sun so she doesn't get sunburnt or heatstroke. This time she also has a partially shaved head and healing scars. We can't put a hat on her or completely cover her in sun protection lotion.
Basically, halo wearing affects your life in both winter and summer. It's just as difficult to keep cool as it is to keep warm. Ironically, Lucy's summer halo appears to have much more sheepskin than the winter one. The summer one covers her neck a lot more, whereas the winter one left her neck exposed to the cold.
We are trying to keep things as normal as possible, and using Lucy as a guide we are getting out when we can, just not for long.