Using a timer, a soft towel, and a bag of frozen peas or blueberries, ice your injection site for 10 minutes each hour while you're up and about. Small frozen objects will cool the area without pressing sharp edges into your skin. Do not lay back with an ice bag directly on the site and do NOT fall asleep with an ice pack on your neck; frostbite hurts! Try to remain upright without engaging in anything too vigorous.