The neckwarmer is very important. Make sure if you don' t have a coverall type suit that whatever you have stays tucked in and doesn' t let a draft in up your back. If your kidneys get cold, the rest of you is going to get cold. I gave my bro-in-law a X-changer, which is a mask that, as you breathe, heats coils that then heat the incoming air. He says it has been very effective at keeping him warm. If you have the room in your boots, the toasty-toes chemical heat packs are nice. You just have to have room to circulate some air around them to make them work. If your boots are too tight, forget it.