Final answer:
Bergman's and Allen's rules explain the relationship between body size and temperature, and are relevant to heat/cold stress. These rules help organisms adapt their body size and shape to cope with temperature variations.
Step-by-step explanation:
Bergman's and Allen's rules are ecogeographic rules that explain the relationship between body size and temperature. Allen's rule states that animals living in hotter climates generally have longer extremities than those living in colder climates, while Bergmann's rule states that within a broadly distributed taxonomic group, populations or species of larger size are found in colder environments, whereas populations or species of smaller size are found in warmer environments. These rules are relevant to heat/cold stress because they help organisms adapt their body size and shape to cope with temperature variations. For example, a larger body size can help retain heat in colder environments, while longer extremities can help dissipate heat in hotter climates.