- Joined
- Mar 17, 2003
- Messages
- 930
I have noticed recent discussion of and a few adverts for 60 hour heat packs - or even 72 hour. Please be advised that 40 hour heat packs are the standard for overnight arachnid shipping and a better choice. Their "heat curve" (i.e., how long they take to reach their peak and maintain appropriate temperature/heat production) is ideal for the time period of overnight shipment. 60 hour+ heat packs do not reach their peak during less than 24 hours of packing/transit. I recommend only using these longer duration heat packs for extended shipping such as 2 or 3 day service (e.g., Priority Mail). They work well for shipping feeder insects such as roaches via PM. I never recommend or condone shipping arachnids via 2 or 3 day services. (20 or 30 hour heat packs are not good for overnight shipping because they get too warm too quickly and will not produce sufficient heat in case of a day's delay).
One last thing... over the years I have had more problems due to high heat than cool temps. Heat packs should only be used when necessary and their should be a buffer between packed animals and the pack itself. Chilled spiders often will revive at room temperatures (do not rush this by providing a heat source), but overheated spiders will quickly dehydrate and die.
Loosely wrapping a pack in one layer of newspaper or paper towel can dissipate the heat slower and be a protective layer. Also, since the heat is produced by the oxidation of fine iron particles (rusting), the amount of pack surface area exposed regulates the heat. Place the red strip containing the air holes outward and cover other parts of the pack or partially cover the red strip as necessary to reduce/control temperature.
My normal procedure is to tape the heat pack to the inside of the top styrofoam piece (of course with the red stripe facing out/down). The packing tape leaves about a 1 x 3" strip down the middle of the pack exposed.
Best regards, Michael
One last thing... over the years I have had more problems due to high heat than cool temps. Heat packs should only be used when necessary and their should be a buffer between packed animals and the pack itself. Chilled spiders often will revive at room temperatures (do not rush this by providing a heat source), but overheated spiders will quickly dehydrate and die.
Loosely wrapping a pack in one layer of newspaper or paper towel can dissipate the heat slower and be a protective layer. Also, since the heat is produced by the oxidation of fine iron particles (rusting), the amount of pack surface area exposed regulates the heat. Place the red strip containing the air holes outward and cover other parts of the pack or partially cover the red strip as necessary to reduce/control temperature.
My normal procedure is to tape the heat pack to the inside of the top styrofoam piece (of course with the red stripe facing out/down). The packing tape leaves about a 1 x 3" strip down the middle of the pack exposed.
Best regards, Michael
