Personal factors consider the individuals’ gender, age, the clothing level, the individuals state of health and the quantity of physical activity. Starting with gender, males on average give off 15% more heat than females meaning a female individual in the same environment may feel considerably colder than the opposing sex in the same environment. Age is another factor to take into consideration, a 25 year old would have much better blood circulation and a higher metabolic rate than a 75 year old. This means that an elderly person is more likely to feel colder than a young person in the same environment, furthermore the 75 year old in question could be more sensitive to the sound and lighting conditions around them. Quality of health can also have an impact on a persons perceived level of comfort, some conditions such as a dysfunctional liver, bodily infections and auto immune disease can make you produce more heat than normal. Furthermore, conditions such as an underactive thyroid or anaemia, can make you feel considerably colder. When someone has an illness, they can feel especially susceptible to direct light, loud noises and stuffy humid environments. Another factor is an individual’s level of physical activity, humans give off approximately 70 watts while sleeping, between 120-160 watts while carrying out light working activities and between 400-700 watts when carrying out heavy physical activity. The level of physical activity will have a detrimental impact upon an individual’s comfort levels, too much physical activity without our thermoregulatory system could result in serious injury or even a fatality. The final personal factor is an individual’s clothing value, and this must be proportionate to the environment. It would not be comfortable for an individual to wear a heavy goose down jacket in 25 degree heat and additionally it would not be comfortable for an individual to wear shorts and a vest in 5 degree heat.