Heck, we have below zero temperatures.  Lord knows what the chill is.
I'd ask the dock about much change in the pain med.  The rule of thumb  
seems to be that over the counter pills are around about half strength so  
you may be able to double the package lable dosage without getting into  
trouble, but I'd consult with someone who knows.  I knew it was time to  
get to the doc when I was not getting through the day on a double dose of  
aleve, which had served me well for a couple of years.

Most of the meds have a point where higher doses either haven't shown greater
efficacy in trials or where the potential increase in side effects outweighs
any.  Let's see, according to rxlist.com, voltaren can be given in doses as
high as 200 mg/day.  

If the severe pain you are having today just happens a day or two here and
there, then maybe you can ask your doc about taking more voltaren on those
days or perhaps having something else such as tramadol (Ultram) to help you
get through these times of breakthrough pain.

I would check with your doctors.
It is always possible that you have some condition which would be
adversely affected by increased dosages of any of your meds.

Remember that no two people react the same way, and what works well for
somebody else might be dangerous for you, or vice-versa. Many of the
over the counter meds have serious side affects if you take too much of
them, and your "too much" might even be the suggested dosage on the
label.

The other thing to keep in mind is that people have a tendency to
acclimate to medicines so that after a while they just don't work for
you any more. Ask your RD if MAYBE he/she should change you to another
medicine which might be more effective.