Basically Is cellular respiration what we 'turn to' when we need energy according to the basic chemical reaction glucose + oxygen -> carbon dioxide + water I noticed that water is produced as a byproduct. Does this mechanism act to cool us down also? A certain amount of exercise in summer will produce more sweat than that same amount in winter. Does that imply more cellular respiration went on during summer in though the work done was the same? Therefore more glucose and other energy reactants in our bodies is burnt. Meaning more weight loss etc. So is that why its better to do a workout in hot conditions and sweat more? And why people can loss weight simply sitting in hot saunas? Or is the water produced in cellular respiration too small for cooling purposes? Note: I am not looking for weight loss myself but just curious about how the human body works and the methods of weight loss.