Without them, your product may be compromised from an unnoticed breach in your cold chain. The coldmark turns from clear to violet when the temperature goes below a predetermined threshold.Coldmark indicators help you determine if your products have gone below an acceptable temperature. SpotSee„¢ ColdMark„¢ Freeze Temperature Indicators, -3°/-26°F, 100/Box benefits: delivers irreversible evidence of exposure to unacceptable temperature conditions provides cost-effective solution for last mile monitoring enables easy accept/reject decisions to be made assists in verifying the adequacy of cold chain packaging aids in compliance with regulatory guidelines.