Relief Pak Brand Hydrocollator Moist Heat Packs (10" Round) by Relief Pak. $17.95. Relief Pack brand name Hot Packs are the exact same high-quality hot packs used in physician, physical therapy, and chiropractic offices worldwide. When heated, they provide up to 30 minutes of reusable therapeutic moist heat. Recommended for use with Relief Pack Terry Covers, or simply place in a heavy towel to prevent heat injury while hot.