When using any type of transdermal patch you should be very careful to avoid being out in the heat as well. When your body gets heated up (in warm weather or with a fever), your pores open up which will allow the drug to be "dumped" into your system at levels in which is was not intended to be. It's a no brainer, I'm surprised that the medical professionals in this case did not catch it immediately.

Please use caution when using the patch and going outside during these unusually hot summer months.