Temperature (thermal radiation) -

Temperature problems with a product can stem from internally generated heat or heat created from external IR (infrared), visible light and UV (Ultraviolet) radiation impinging upon the product. This thermal radiation (a part of the electromagnetic spectrum) is considered 'non-ionizing radiation'.

This is another very common wear and tear issue and it is fairly well heeded during product development. But, one needs to pay close attention to the unanticipated influence of temperature on the product, such as thermal shock and widely fluctuating temperature ranges, which may effect the long term form, fit and functionality of many of the components within the product.

Examples of Temperature caused product failures:

• Most types of batteries have very defined temperature ranges in which they can hold a maximum charge and in which they can be optimally charged. This may limit a portable product's usefulness.
• Radiated heat can effect a product's usability: i.e. a powered component may heat to a temperature that prevents proper operation until it is cooled down.
• Mechanical lubricants and various types of seals can eventually fail if they are used outside their guaranteed temperature ranges.
• Components of dissimilar materials that are required to fit together need to be matched for temperature related expansion/contraction characteristics.
• From a colleague: "I have had on going battle with the food company in Vermont. I finally won my point when they took time to look at the map and realize that 20 degrees in Vermont in January was 75 in Galveston and now 55 in NC. So they found that they should use more ice packs in wintertime than they had planned on. Unplanned packaging techniques caused spoiled food."