Which effect is NOT produced by the application of heat in hydrotherapy?

The application of heat in hydrotherapy is known for producing several physiological effects on the body, including increased circulation, decreased muscle tension, and pain relief. When heat is applied, it causes vasodilation, which leads to improved blood flow and circulation in the tissues. This increased circulation can help deliver more oxygen and nutrients to the affected areas while facilitating the removal of metabolic waste.

Heat also has a relaxing effect on muscles, leading to decreased muscle tension. This reduction in tension can enhance flexibility and range of motion, providing further benefits during therapeutic interventions. Additionally, heat is commonly employed for its analgesic properties, helping to alleviate pain and discomfort associated with various conditions.

In contrast, a decrease in circulation is not a typical effect of heat application. Instead, heat generally promotes increased circulation, making it the correct answer to the question regarding the effects of hydrotherapy.