Question is in the title basically. If one were running a fever of say 103 degrees would it then be that much harder for one to experience hypothermia, since your body temperature is being kept artificially high by whatever’s causing the fever?
At first, possibly. But your body will have fewer reserves and will quickly drop the core temperature. In the end, I think being healthy and able to burn resources efficiently is more important that the initial body temp.
No, and in fact it will very likely make you more susceptible to the environmental conditions that cause hypothermia. Pyrexia (moderate hyperthermia, or in layman’s terms, “a fever”) has the core body temperature only a few degrees above mean body temperature (~98-99 degrees F), and is typically an immune response to infectious or immunological diseases. The immune system releases cytokine factors (message-carrying proteins that signal the body’s thermoregulatory control in the hypothalamus) to increase temperature which then increases blood flow to the extremities. In a fevered state, the body is running at high speed, both fighting the (perceived or real) contagion and processing liquid through the eccrine sweat glands to carry away waste products. The normal thermoregulatory processes are subverted to this end, so the means by which the body protects itself from hypothermia–reducing blood flow and heart rate, constricting capillaries in the extremities, et cetera–are no longer functioning.
The loss of heat by both conduction and evaporation will increase, meaning that the body loses heat faster and in an uncontrolled manner, hence why people with intermittent fevers experienced chills and shivering in between bouts of heat, and why it is critical for someone with a fever to intake plenty of readily absorbed fluids (water, dilute juice, et cetera and not diuretics like coffee, strong tea, or soda). Even if it did serve to warm the body without cooling effects or dehydration, it is only by a few degrees, whereas the conditions that lead to hypothermia are gross differences in air temperature or submersion in a cold liquid which enhances conductive heat transfer by several orders of magnitude. You can get hypothermia in 80 deg F water if you stay in long enough, even though that is a perfectly comfortable temperature in air.
External hyperthermia–heat stroke–is an overload of the body’s temperature regulation by an exterior high temperature source. It does not have the same causes as pyrexia, and the treatment–cooling with cold water compresses, ice packs, or in extreme cases, submersion in an ice bath (the later should only be done by experience medical personnel, as this can result in loss of thermoregulatory control and “rebound hypothermia”)–is intended strictly to carry the extra heat away from the body when the body’s normal cooling mechanisms (primarily sweating) are inadequate or have shut down.
Well there’s an answer and then there’s an answer. Thanks SOAT!
Stranger, I’m really glad that bear didn’t eat you.
No, it ate the other guy. He was slower.
How long is long enough, while we’re on the subject? 80 is a nice, warm summer pool temperature and while it’s not quite bathwater-warm, it’s not going to feel “cold” to anybody (not that I doubt you’re telling the truth–I am sure you’re right).
The thing is, I and my family used to swim in water at this temperature for hours (with bathroom breaks of course) while growing up and I never got hypothermia. Are you talking on the order of spending days at this temperature?
It is one thing to be splashing and playing in the water, especially if you are climbing in or out or are only partly submerged (as on an innertube or floaty) and in the sunlight; it is quite another if you are not moving much, under clouds, or at night. Here is a standard table that indicates hypothermia exposure times to water temperature. At ²80¡F, exposure time for a healthy adult is 3 hours to indefinite, but exposure for someone who is exhausted (from panic or trying to swim to safety) is 3-12 hours. At ²70¡F (where “cold” officially starts), exposure times drop to as little as two hours (obviously applying to someone with a low subcutaneous fat content and probably borderline anemic). At ²60¡F exposure times drop to a few hours or less, and it just gets worse from there. All of these temperatures would be perfectly fine in air, though, even with minimal clothing. There are cultures that wear essentially no insulating layers at mean tempetures ~40¡F without harm, but if you swim in 40¡F you’ll be doing good to make 15 minutes without shivering and half an hour before experiencing hypothermia.