Heat is an environmental stress that negatively impacts the survival of humans by disturbing homeostasis. Heat can result in many things such as heat rashes, heat exhaustion, and heatstroke. Heat rashes occur when the sweat glands become clogged from too much sweating or not enough circulation to the area. Heat exhaustion may occur after you’ve been exposed to high temperatures for several days and have developed dehydration. Heat exhaustion can cause headaches; fatigue, nausea, vomiting and can reduce energy levels Dehydration, which occurs when the amount of fluid coming out of the body exceeds the amounts of fluids coming into the body. Heatstroke is caused by prolonged exposure to high temperatures or by doing physical activity in hot weather. You are considered to have a heatstroke when your body temperature reaches 104 degrees F or higher.

Humans have adapted to heat short term by sweating. We lose water by sweating. It’s the body’s way of trying to cool itself down. It is imperative that you replenish the electrolytes you’re losing when you sweat. Sweat makes your skin feel cooler when it's wet. And when it evaporates it removes some heat. For sweat to cool your body temperature the water must evaporate. 

Facultative adaptation is vasodilation, which expands the capillaries to allow greater blood flow to the skins surface, dispersing heat from the body. Sweat secretion stops when body temperature returns to normal. Blood vessels supplying blood to the skin can swell or dilate - called vasodilation. This causes more heat to be carried by the blood to the skin, where it can be lost to the air. This reduces heat loss through the skin once the body’s temperature has returned to normal.

Developmental adaptation for heat is being able to walk on two feet rather than on four and also the shape of our bodies. Bipedalism and our long body shapes. This contributes to our core and our limbs which can help provide more body area for sweating. If we were to walk on all four, our bodies would be more exposed to the sun. Especially our backs. Standing straight and only walking on two feet also enables us to walk fast which can lead to cooler breezes. 

Humans have adapted to heat culturally by utilizing air conditioners and fans, swimming pools and water parks. We can have these in our homes, cars and at work. Although this can be a short term adaptation humans are able to cool down quickly without having to wait for their body temperature to drop to achieve coolness. Air conditioning help with heat stroke and heat exhaustion by quickly reducing the body’s temperature. Water parks and swimming pools are other cultural adaptations that we can take advantage of. Water parks and pools are used to cool off and also for enjoyment purposes. 

The benefit of studying heat on human variation helps us to figure out how to adapt better to our environment. We know how deal with it, embrace it, or tolerate it. We know we have to stay hydrated and replenish what our body loses from sweat, we can protect our skin by using sun screen, use air conditioning and recreational fun to stay cool. The benefits of studying human variation would allow us to evolve and adapt better in different environments. This would allow us to learn how to adapt to not only heat, but other environments. 

You couldn't use race in relation to the adaptations because these adaptations are necessary for all races. Everyone has the ability to adapt to different environments, it is not unique to any race. Humans have a strong capacity to adapt to heat. Individuals exposed for the first time to a hot climate can adjust over a period of 10-14 days. This involves a lowering of the body's core temperature and a reduction of the heart rate and metabolic rate. All races are able to adjust and do this.