A question about heat stress.

[PCB]

I'm sure everyone has heard of this before, that you are more likely to have a second heat stress episode after you have suffered from it once before. Everyone says this, but is it really true? If so, then why?

Thanks in advance.

PC

[Just Plain Ruff]

my understanding is that Yes you are more susceptible.

[MedicRN]

In short, the heat injuried patient's internal thermoregulation is shot.

[Just Plain Ruff]

I had a heat exhaustion illness about 8 weeks ago. Mowed the lawn in 95 degree heat, didn't drink any water for the entire time.

spent the entire afternoon before my wife got home lying on the couch.

Wife started to pour water down me and it wasn't till the next day that I felt back to normal. I believe I started to cease sweating but by that time I was done with the lawn.

Ever since, I can only go out in the heat for about an hour or so before I begin to feel sick.

[EMSGeek]

The body is always working towards homeostasis but when it has become so taxed that it can no longer do so bad things happen. In the case of heat stroke we are talking about the bodies ability to regulate temperature. The bodies main methods of temperature detection is the skin (hence why burn patients have trouble regulating temp.) so when the skin is compromised the body can not detect temperature. The way the body actually adjusts its temp. is through sweating which requires water. If the skin is compromised or the body doesn't have enough water it needs time to redevelop those abilities so, yes, once you have had a heat related event you are predisposed to have another. The body needs time, usually a day or more, to get back to normal.

[Dustdevil]

In short, the heat injuried patient's internal thermoregulation is shot.

That's it in a nutshell. The regulatory centre in the hypothalamus becomes unstable, resulting in several mechanisms becoming unreliable, including the kidneys and the ability to sweat. There is a common misconception that the reason heatstroke patients don't sweat is because they are dehydrated. This is only partially true, and only in exertional heatstroke patients. In most classic heatstroke cases, the patient is not dehydrated from sweating out. The body is simply not being told to sweat by the thermoregulation centre. This dysfunction can continue for weeks or a lifetime. And those with a history of heatstroke should be given follow-up testing at regular intervals to monitor this.

Excellent question! I love it when somebody wants to know why something actually happens, instead of just accepting factoids without explanation! :thumbright:

[Lilacmedic]

Damage to the Hypothalamus or injury to the limbic area will also increase the risk of suffering from heat stroke again the following meds also play havoc with mr. Thermostat..

(1) psychotropics, which affect psychic function, behavior, or experience (e.g. haloperidol or chlorpromazine)

(2) medications for Parkinson’s disease, because they can inhibit perspiration.

(3) tranquilizers such as phenothiazines, butyrophenones, and thiozanthenes.

(4) diuretic medications that affect fluid balance in the body.

[Richard B the EMT]

Ruffems, you stated you had an "almost repeat" episode, within a 3 month period?

With that in mind, I'd like to expand the question to ask: Can one can be susceptible to second or more episodes of heat related diseases at, for a time frame within this question, over one year's time from the initial episode?

[AZCEP]

In short, the heat injuried patient's internal thermoregulation is shot.

Hey, what happened to the "why do you think this happens" approach?

[PCB]

Ruffems, you stated you had an "almost repeat" episode, within a 3 month period?

With that in mind, I'd like to expand the question to ask: Can one can be susceptible to second or more episodes of heat related diseases at, for a time frame within this question, over one year's time from the initial episode?

Actually, this is why I asked the question (beyond my normal inquisitive nature). We had a man lose conscienceness the other day. He suffered what seemed to be the same thing last summer; loss of concusness, seizure, vomiting, responsive only to pain. The ED attributed the episode last year to heat, but this year they are still undecided. I did a survey of the work area 2 hours prior to his last episode and the heat index was below 90 F. He was hydrated and had eaten 2 hrs prior.

Dust, you mentioned "follow-up tests" for those with a history. What testing would be useful?

Thanks for the response.

PC