Heat exhaustion is serious. Heat exhaustion is a sign that the body is unable to cool itself and is losing the fight against heat.

Typically, this stage follows heat cramps. You’re hot, you sweat a lot, and in the process you dehydrate and dilute your electrolytes.

Its onset can be sudden with symptoms of fatigue or dizziness, as your body diverts blood away from the brain and to the skin in an attempt to shed excess heat. Blood also pools in the lower legs and feet. Your boots may feel unusually tight. When sitting on a motorcycle for prolonged periods, your hands may swell.

Other symptoms include a general feeling of being unwell, nausea, and heavy sweating. There may also be muscle cramping, headache, and weakness. Your skin may feel cool and clammy to the touch as your circulatory system can no longer transfer heat to it.

On the other hand, your awareness may be affected so gradually that you don’t realize it. It can sneak up on you since increased body heat affects your judgement and situational awareness. Suddenly your brain momentarily stops processing and you’re unexpectedly riding off the road.

The excessive fluid loss results in lower blood volume. The blood thickens and become less effective in carrying heat to the skin. This can also progress to reduced blood flow to organs.

Left unchecked, it can rapidly lead to heat stroke.

Someone in this condition needs to get out of the heat, possibly under some shade. Drink sport drinks if available in order to replace fluids and electrolytes. For more serious cases, lie down and elevate feet. It’s imperative to determine that the person is beginning to feel better and is not progressing towards heat stroke.

Note that once you have experienced even mild heat exhaustion, you will need a day or so out of the heat in order to recover. During this time you will probably have low tolerance for heat. Keep this in mind if you are out on a multi day ride. Once you bust the limit, you’re ride is sidelined.