Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: DoctorBeaver on 17/02/2008 00:26:45

Title: Ouch... it's cold. Ah, that's better - it's cold. How does freeze spray work?
Post by: DoctorBeaver on 17/02/2008 00:26:45

Going up the stable yard early morning during this cold weather has got me wondering. Why do my fingers hurt when they're cold?

I wear gloves, but the metal handles of the wheelbarrow & mucking-out tools make my fingers freezified and they start to hurt.

Conversely, I've got 1 of those therapeutic freeze sprays (like Deep Heat but opposite) and that eases pain.

So, how come cold weather makes my fingers hurt, yet the freeze spray relieves pain?

Title: Re: Ouch... it's cold. Ah, that's better - it's cold. How does freeze spray work?
Post by: another_someone on 17/02/2008 01:48:51

As an analogy - if I push you head underwater for 60 seconds, you will be thrashing around and generally making a great fuss of your predicament; but if I push your head underwater for 10 minutes, you will stop complaining about things.

In any case, the freeze sprays, although they are very cold, they only cool locally, so they can paralyse the nerve endings, but wont actually cause frostbite.

Title: Re: Ouch... it's cold. Ah, that's better - it's cold. How does freeze spray work?
Post by: DoctorBeaver on 17/02/2008 08:16:07

You've confirmed what I thought about cold paralysing nerve endings. So, why do my fingers hurt from the cold on frosty mornings? What is the actual mechanism that makes them hurt?