There are really three ways that people try to control how warm or cool they are -- they live in houses rather than outside, they heat or cool those houses and they wear clothing.
Believe it or not, the picture that you see is of two people in summer clothing. You are quite right, we are looking at a thermogram again.
The hottest temperatures are white, then red, green, blue and magenta (light purple) and finally black (the coolest).
The small picture in the upper corner shows what the man and woman look like to our eyes. The woman in wearing a bikini; while the man is wearing a short-sleeved shirt and light pants. Because the woman is wearing very little clothing she is giving off a lot of heat ... nothing blocks it. The man has far less heat loss.
You can see that in the summer, when you want to be cool, a bathing suit is a better choice. Click on the buttons to see how other types of clothes change the way our bodies radiate heat.