ALL PLASTIC DISPOSABLE THERMOMETER

A new and useful all plastic disposable thermometer is disclosed, which dispenses with the prior art employment of an aluminum or other metal-based substrate. The novel thermometer can either be employed with opaque indicator means or with heat-sensitive compositions of matter that change color with a change in phase. The thermometer comprises non-metallic polymeric heat-conducting embossable flexible base layer having one or more spaced cavities defined therein to determine a like number of predetermined temperatures in a predetermined temperature range, with a like number of different thermally responsive compositions of matter in the cavities. Each thermally responsive composition of matter is associated with one of the predetermined temperatures. The thermometer also has a non-metallic sealant layer in sealing engagement with the base layer, and which overlies each of the cavities. There is obtained a non-vented substantially vapor-impermeable enclosure for each cavity between the base layer walls and the floor of the cavity and the sealant layer. At one of the base layers, the sealant layer is transparent.