Safety modifications to mobile hypothermia units

Major safety deficiencies of older mobile hypothermia units are described. Problems include absence of high or low temperature output limitation or of visual warning of abnormal operating temperatures. Modifications described provide two high temperature thermostats and one low temperature thermostat, which shut the unit down if the temperature limits are exceeded. Visual and auditory alarms were also added. Operators of mobile thermal units should be aware of the major safety deficiencies of some older models, and should insist on either modification, where appropriate, or replacement.