Blood Coagulating

[Pencey]

Does cold weather or rain speed up the coagulation of blood to keep someone who just slashed their wrists alive a bit longer until help arrives?

[Fortean]

Not really. Bad weather is not going to speed the healing process for a wrist-slasher. A resourceful person might realize, in a very cold situation, that a frozen piece of metal might help staunch the blood loss by freezing the wounds, (as would cauterizing them with heat); but, a couple of tourniquets are going to be much more effective for first aid.

[Augie Kestrel]

This is for a script, right?

[filmcarver]

If the wounds are more superficial than deep, then the answer would likely be "yes" because as the core body temp is lowered, the brain instructs the adrenal glands to secrete, which clamps down your peripheral smaller vessels and capillaries and shunts warm blood to the core organs. That's why your hands and feet get cold before anything else.

Veins bleed much more slowly than arteries, and generally would stop bleeding before death, so better chances again if arteries are not severed. Slash an artery and you better pray you are awake enough to stop that puppy fast....you have about 45 seconds....a normal heart pumps 5 liters per minute, just over a gallon of blood!

If you have details of how you want the scenario to unfold, I'll be happy to guide you based on medical accuracy.

[pantalone]

wouldn't rain just wash off the blood? The clotting would be inhibited because previously clotted blood would wash off.

Now, blood on ice, that's cool.

[filmcarver]

It's not an exact science or situation. You are assuming the clot exists only outside the vessel, but that isn't true, it will traverse inside the vessel as well.

Whether it's cold, adrenaline, a local vasopressor agent, physical pressure, anything that clamps down blood flow would hinder bleeding to death, just as there are situations that might prevent it.

[BeefMissile]

Check these sources for details of CSI/body functions/etc.

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