Processing cattle during the winter months increases the stress on both cattle and workers. Colder temperatures can also cause the liquids in syringes to freeze. As veterinarians note, that is more than just a nuisance. Proper handling of vaccines requires that the products are protected from extreme heat and cold. North Dakota veterinarian Morgan Dallman developed a heating system that keeps syringes warm. He purchased a heater that attaches to a small propane tank that he sets beside a 55-gallon barrel that has a hole cut in one side. The heater blows warm air into the barrel, and Dallman uses the top of the barrel to set his syringes on between uses. He says the system works best inside a barn or shed, but will work outside if the system is protected from the wind. Dallman offers one caution, however. Do not place the heating element inside the barrel, as it needs fresh air flow to work properly.