Final answer:
Moderate heat stress is a topic within Environmental Physiology and Exercise Physiology, which study how organisms respond to changes in their environment and the effects of exercise on the body.
Step-by-step explanation:
Heat stress, where the body temperature is higher than the environment temperature, is a topic that falls under the subject of Environmental Physiology. Environmental Physiology focuses on understanding how organisms respond and adapt to changes in their environment, such as temperature.
When the body is exposed to heat stress, it triggers various physiological responses, including sweating, in order to regulate body temperature. This response is part of exercise physiology, which studies the effects of exercise on the body.
In conclusion, the subject that best relates to the concept of moderate heat stress is Environmental Physiology and Exercise Physiology.