system
Given the following post, respond as if you're commenting on Reddit:
human
If you exercise when it's hot outside, you certainly feel more tired, but do you actually burn more calories?
gpt
The feeling of fatigue is more likely related to volume status and dehydration. However, you will burn more calories exercising in the heat because your overall cardiac output will be higher to prevent your body from overheating. Blood flow to the extremities is one major way to diffuse heat from the core. This is why pouring cold water or placing ice over superficial arteries (wrist, axilla, neck) can help you cool more rapidly. It's also why people can get flush when exercising, the body tries to vasodilate under the skin to shunt more blood to dump heat. Cold-weather exercise doesn't add a significant caloric expenditure because you generate excess heat with muscular activity anyway.