I have observed a strange thing happening with me these days. In India, month of March to May are of Summer with extreme heat, May to be worst. Midday, the mercury rises up to 40oC. I was walking on a long plateau for close to an hour or so in the afternoon, with ambient temperature of about 40oC. I was well hydrated. The water in the hydration pipe (and not the bladder) was a bit hot due to the sun. Yet, I took a sip and then came the colder water. I immediately got goosebumps as it felt cold. That happened frequently. Have anybody observed this? It didn't affect my performance visibly, but I felt that really strange. Is that an issue?
Okay, I think I have figured it out a bit after discussing with a few fellow mountaineers.
There are 3 major factors to consider:
- Heat and Humidity
As I had mentioned, it was pretty hot and humid out there. It was almost midday and I was alone and had climbed up close to 4000 ft that morning and descended about 2000 ft with a little more than 3 ltr of water consumed. Whether I was doing okay with hydration or not is another question but I had not observed any of the symptoms of dehydration at all.
I have observed that on a humid day, one may end up drinking some quantity of water and perspire more due to humidity and so loose more fluids than what he/she has consumed through the day. After a certain exhaustion, with that amount of heat and humidity, the thermal regulation system might get overwhelmed. That would result in increasing the core temperature. The exertion would inhibit the evaporation of sweat further compromising the body’s thermoregulation mechanism.
Another question arises when I ask myself "Was I consuming enough fluids to remain hydrated?" The other factor that impedes the thermoregulation mechanism is Dehydration. It has its impact on sweat production. So even though I had drank enough water, the humidity was causing an even greater Perspiration rate than usual. Then there are two possible situations: both resulting in Blocked sweat pores.
- The excessive sweating blocks the sweat pores (Eccrine Sweat Glands), the perspiration accumulates on the skin, it naturally evaporates. As the sweat evaporates, it cools down the skin surface and the Thermoregulation mechanism goes haywire resulting in a Heat Stroke.
- You don't continue drinking water and continue to sweat, and finally get so dehydrated that no more sweat is produced. That is when you see rashes on the skin.
In my case, those were early symptoms of a Heat Stroke.