How should specimens that must remain cold be sent?

Specimens that must remain cold should be sent with ice packs, as this method effectively maintains the necessary low temperature during transport while preventing the specimens from freezing. Ice packs provide a consistent cooling source that is important for preserving the integrity of biological samples, which can be sensitive to temperature fluctuations. This approach is particularly useful for specimens that need to remain at temperatures above freezing but still below typical room temperatures.

Dry ice might be extremely cold, which is beneficial for certain types of specimens that require freezing, but it can also pose a risk of freezing and damaging other types of specimens that are not meant to be exposed to such low temperatures. Sending specimens at room temperature is unsuitable for items that need to be kept cold, as this could compromise their quality and viability. Gel packs may have some cooling capacity, but they are often not as effective as ice packs for maintaining the required temperature range for many specimens during an extended shipping period. Thus, ice packs represent the most suitable choice for ensuring specimens remain adequately cooled throughout transportation.