Subcutaneous (SC) injection applications are the process of administering the drug to the loose connective tissue under the skin and is one of the most frequently applied parenteral drug administration methods among nursing practices. SC injections, which are frequently performed by nurses, often result in complications such as hematoma, ecchymosis and pain at the injection site. Although the field of healthcare is developing day by day, injection applications can still be painful and uncomfortable. These procedures increase the individual's stress levels before the procedure, causing them to experience fear and anxiety and reducing patient satisfaction. This may cause the application to fail or be repeated. Many nonpharmacological methods are applied to prevent or reduce these local side effects in subcutaneous injection applications. Cold application is accepted as an effective and easy-to-use method for SC injection. Cold application may also constrict peripheral blood vessels, reducing blood flow to the tissue and thus preventing ecchymosis.

When the national and international literature is examined, there are studies using cold application to reduce pain and ecchymosis due to SC injection in adults. This study aimed to evaluate the effectiveness of cold injection, which is considered an alternative to cold therapy, in reducing pain and ecchymosis due to SC injection application. No study has been found in the literature evaluating the effectiveness of cold injection in preventing pain and ecchymosis due to SC injection application. Therefore, it is thought that this study will make a significant contribution to the literature and create a simple, comfortable and cost-free innovation. Preparation and use of cold injection is simple, easy and comfortable. It is anticipated that patients will be able to easily follow the procedure steps during the procedure. Therefore, this study aimed to examine the effect of the cooled needle on the development of pain and ecchymosis in SC injection application in adults.

Subcutaneous (SC) injection applications are the process of administering the drug to the loose connective tissue under the skin and is one of the most frequently applied parenteral drug administration methods among nursing practices. SC injections, which are frequently performed by nurses, often result in complications such as hematoma, ecchymosis and pain at the injection site. Although the field of healthcare is developing day by day, injection applications can still be painful and uncomfortable. These procedures increase the individual's stress levels before the procedure, causing them to experience fear and anxiety and reducing patient satisfaction. This may cause the application to fail or be repeated. Factors affecting pain and ecchymosis caused by subcutaneous injection include injection time, injection site, drug injected, dose injected, and needle size. Many nonpharmacological methods are applied to prevent or reduce these local side effects in subcutaneous injection applications. Cold application is accepted as an effective and easy-to-use method for SC injection. Cold application may also constrict peripheral blood vessels, reducing blood flow to the tissue and thus preventing ecchymosis.

When the national and international literature is examined, there are studies using cold application to reduce pain and ecchymosis due to SC injection in adults. This study aimed to evaluate the effectiveness of cold injection, which is considered an alternative to cold therapy, in reducing pain and ecchymosis due to SC injection application. No study has been found in the literature evaluating the effectiveness of cold injection in preventing pain and ecchymosis due to SC injection application. Therefore, it is thought that this study will make a significant contribution to the literature and create a simple, comfortable and cost-free innovation. Preparation and use of cold injection is simple, easy and comfortable. It is anticipated that patients will be able to easily follow the procedure steps during the procedure. Therefore, this study aimed to examine the effect of the cooled needle on the development of pain and ecchymosis in SC injection application in adults.

The research will be conducted as a randomized controlled, experimental clinical trial. The population of the research will consist of patients who applied to Erciyes University Health Application and Research Center General Surgery Service between the dates of the study. As a result of the analysis, it was decided to include a total of 60 people in the sample of the research. In collecting research data, the Case Report Form consisting of the Individual Introduction Form, Visual Comparison Scale and Ecchymosis Tracking Chart, created by the researchers by scanning the relevant literature, will be used. The data obtained in the research will be analyzed using the SPSS 24.0 program. Care will be taken to comply with ethical principles at every stage of the research. Before starting the application, an Academic Board Decision, ethics committee approval from the ERÜ Faculty of Medicine Ethics Committee and institutional permission from the ERÜ Health Application and Research Center will be obtained. Participants will first be explained the purpose of the research, given information about the research, and their written consent (Informed Volunteer Consent Form) will be obtained.

Inclusion Criteria:

1. Able to speak and understand Turkish,
2. Those between the ages of 18-65,
3. Oriented to place and time,
4. Having no vision or hearing problems,
5. Not using psychiatric medication due to any psychiatric disease,
6. Not using central nervous system medication,
7. Not using narcotic analgesics,
8. Having a Visual Comparison Scale pain score of zero at the time of application,
9. Those who have not had SC injection in the last month,
10. Low molecular weight heparin therapy is ordered (Enoxaparin Sodium 1*4000 IU),
11. Having an average pressure pain threshold of 8-16 pounds (Lb) with the Baseline Algometer device,
12. Has normal platelet, INR, and aPTT values,
13. Individuals who volunteer to participate in the study and sign the written voluntary consent form will be included in the research.

Exclusion Criteria:

1. Vital signs not within the reference range,
2. Those with signs of phlebitis, scar tissue, dermatitis, incision and infection in the area where the intervention will be performed,
3. Having had a mastectomy,
4. Patients who declare that they are addicted to alcohol and drugs will not be included in the research.