The article Muscle Strains & Heat Therapy: Warming up Your Pre-Workout Routine says:
Applying heat therapy to chronic injuries and taking preventative measures for strained muscles before exercise helps increase the elasticity of joint connective tissues and increases blood flow to the affected area. Devoting time to heat therapy for just 15 minutes before you begin your workout will help relax tight muscles and muscles spasms and future reduce pain and swelling.
To apply heat therapy, I wonder what is preferable between using heat patches, hot towel or hot water (i.e., staying in warm water for X minutes), before exercise.
I looked for information on Google and Google Scholar but haven't found anything, so I'm not sure whether it means nobody looked at it or that it has obvious difference.