Using Ice and Heat
by John Howick
© 2003
I often get asked “When should I use
ice and when should I use heat?” With a sprain or strain,
collagen fibres are overstretched and torn. Tiny blood vessels
are also damaged. This bleeding produces the bruising seen
in a sprained ankle or torn hamstring. Even if no bruising
is seen, there is bleeding inside. If enough collagen and
blood vessels are damaged, swelling appears almost immediately.
A large amount of swelling appearing within the first hour
after an injury is a sign of excessive bleeding and a serious
bone, muscle or ligament injury. In a less severe injury,
swelling develops gradually. Often it is not noticed until
the day after the injury. This swelling is primarily cellular
fluid, not blood, and is related to inflammation.
What causes fluid to leak out? When body
tissue is damaged, chemicals are released which attract
white blood cells to the area to clean up the damaged and
prevent infection. These chemicals also make the blood vessels
and cells in the area “leaky” allowing fluid to
slowly ooze out. The chemicals also cause the nerve endings
to become hypersensitive which leads to pain. After a few
days the damaged blood vessels begin to repair and regrow
but they are very weak. If there is a sudden increase in
blood flow to the area these blood vessels leak and sometimes
blow apart!
So how does this relate to the use of ice?
If we want to minimize the swelling we need to slow down
the blood flow to the area. Ice causes a closing down of
the blood vessels (vasoconstriction). Ice also decreases
firing of the nerve endings (that’s why it makes you
feel numb) and thus decreases pain. Therefore you should
always use ice when you want to minimize swelling and inflammation.
Inflammation is most significant in the first 72 hours after
an injury so you must always use ice in this time period.
Never use heat or hot tubs in this early period. Heat causes
a large increase in blood flow to the area(vasodilation).
I often hear ” I pulled my muscle so I went straight
to the hot tub and my leg swelled up like a balloon.”
Just visualize those poor torn blood vessels getting blasted
with blood rushing to the area like a fire hose turned on
full blast. Fluid and blood pour out into the surrounding
tissue.
What about after the first 72 hours, should
you switch to heat? Inflammation is most significant in
the first few days after an injury but it doesn’t stop
magically when it reaches the 4th. day. The inflammatory
process gradually decreases over time as long as no further
injury occurs and conditions are perfect for healing. We
don’t live in a perfect world and often as we begin
to recover we overdo it. The inflammation, pain and swelling
increase again. Ice is the right choice to treat this. In
my practice, I often continue using ice for 6 weeks or more
after a traumatic injury or with overuse injuries.
When is heat a good idea? Heat gets the
body ready for activity and may prevent injuries. Heat is
best used for chronic injuries where there are no signs
of inflammation. After a muscle strain has healed it is
often tighter than it should be. Heat can make muscles,
tendons and joints more flexible and easier to stretch.
Arthritis can make joints feel very stiff and heat works
well to improve mobility. Other mild chronic injuries cause
an annoying ache and heat can sooth this pain.
What about alternating hot and cold? In my opinion this
is not as effective as using ice or heat by themselves.
I have used it in select cases to decrease extreme swelling
in the foot and ankle. This involved alternating between
a very hot whirlpool and a bucket of ice water. In most
cases I would say stick with ice alone.
How about those creams and lotions you can
rub on that feel hot or cold. These do not change the temperature
of the tissue under the skin so they do not replace the
use of ice or heat. These lotions do stimulate nerve endings
on the skin and can temporarily decrease pain. If they make
you feel better go ahead and use them but don’t forget
to use actual ice or heat when necessary.
Quick rules to remember:
ICE
1. In the first 72 hours always use ice, never heat.
2. Continue using ice as the injury heals whenever you have
signs of inflammation (swelling, heat, redness, pain).
3. Use ice to treat constant, sharp, intense pain and muscle
spasm (when the muscle tenses up and won’t release).
4. Use ice after activity if you think you may have strained
or restrained something.
5. Apply ice for 15-20 minutes. It can be repeated every
hour in the acute stages. Generally 3 times per day is adequate.
6. Always have a thin layer of cloth or paper towel between
you skin and the ice to avoid “frost bite”.
HEAT
1. Use heat before activity to help “warm-up”
and get ready for movement.
2. Use heat to make joints and muscle more flexible and
easier to stretch.
3. Use heat for mild arthritis, achy muscles and general
feelings of stiffness.
4. Apply heat for 20-30 minutes.
5. Check your skin frequently for any signs of burning.
If your skin is too red, remove the heat immediately and
apply ice or cold water to cool the skin.
If you have Raynaud’s Disease
or any other circulatory problems check with your physician
before applying heat or cold.
