Malnutrition was a large problem for the travelers on the Chilkoot and White Pass Trails, and many died from it. Sometimes people suffering from malnutrition ate the bodies of the dead horses left on the White Pass Trail, and became violently ill as a result. It was rumoured that a traveler had used his boots as a source of food by boiling them and drinking the broth after so he could eat something. Physical illness was not the only problem to plague the travelers, as many also went insane from the conditions along the trails. Historians have suggested that the high rate of mental problems recounted were caused by the poor diets of many travelers, added to what may have been poor condition before starting the trails. In addition, along the trail the only shelter against the sometimes -40 degree temperatures were thin tents.