Heat exhaustion refers to a condition caused due to the prolonged exposure to higher temperatures resulting in symptoms like heavy sweating and rapid heartbeats.
Some patients may develop mild heat cramps while some develop serious symptoms like heat stroke that is known to cause life-threatening consequences.
The common causes of heat exhaustion are exposure to very high temperatures, especially when combined with higher humidity, and performing strenuous physical activities.
Overheating of the body
Research studies were conducted to assess whether the changes occurring in the body following the exposure to high temperatures depend on the height of the person. Some studies were also focused on evaluating whether the body of a shorter person reacts differently than the body of a taller person to higher temperatures.
These studies have shown that shorter people are not as likely to get overheated as taller people.
Also, the risk of developing more serious complications like heat stroke is also lower in shorter people.
Differences in the body surface areas and weight
This link could be explained with the help of differences in the body surface areas and weight of people based on their height.
Taller people have a higher weight compared to the shorter people with the same BMI. So, the heavier body of taller people causes them to produce more heat.
When taller people work under higher temperatures, their body produces more heat at a rate faster than it can lose it. So, the total heat generated becomes very high in a short duration.
For example; when a taller person performs intense exercises, the body gets heated up faster. And if the person continues to exercise for long, especially under hot and humid conditions, the body does not get adequate time to lose the heat into the atmosphere.
This happens because heat travels from higher temperature to lower temperature.
If the difference between the temperature is more, then the heat transfer can occur at a higher speed. However, when the body temperature has already increased substantially due to exercising, the difference between the internal body temperature and the outside atmosphere becomes very less. As a result, the heat transfer slows down causing the body to take a longer time to cool.
When the person works out under extremely high temperatures, the process of heat transfer would be almost negligible due to which the risk of heat stroke can increase remarkably in taller people as the heat produced would be more in them.
This is why; taller people are advised to avoid working out or performing strenuous activities under hot temperatures for a longer duration.
These effects in taller people can worsen further when they work in humid conditions because the increased humidity reduces sweating, which is the body’s natural cooling mechanism.
If the weather is humid, it means the amount of water vapors in the atmosphere is already high. So, the rate of evaporation of sweat from the skin surface would reduce thereby slowing down the process of cooling of the body.
These are some reasons why taller people are more likely to develop heat exhaustion and heat stroke due to their higher body weight and the resulting increased amount of heat produced in the body.
On a brighter side, taller people can avoid feeling too cold and stay warmer compared to shorter people during cold weather or winter season for the same reasons. 
The effect of skin surface area
There is another factor that plays a role in determining your chances of heat exhaustion based on your height. Some studies have found that the risk of heat exhaustion is higher in taller people not just because of more heat generated but also due to their higher skin surface area.
Taller people have more skin covering their body than that of shorter people. The more skin surface your body has, the higher would be your body mass. The greater body mass, in turn, can cause more heat to be generated by your body thus increasing your risk of heat exhaustion.
Also, your skin is the location where the droplets of sweat tend to collect before getting evaporated. So, the amount of your skin surface indicates how hot your body is liable to become.
Unfortunately, the heat generated in the body tends to rise to the surface of the skin due to which the skin gets hotter.
So, in taller people with more skin, the body cannot cool down as quickly and efficiently as it tends to heat up. So, the more skin your body has, the more heat it would collect. This explains why taller people have higher chances of developing heat exhaustion and heat stroke, especially when exposed to hot and humid climates.