Reptile & Amphibian Forums

has anyone done controlled tests with heat packs, to see how the temp in a box changes over time?

I ship from florida (warm) sometimes to northern cities (cold). But the boxes have to be packed a couple hours before shipping, and then are at reasonable temps until first unloaded at their destination (or for a plane change enroute). So i want heat four to eight hours into the trip, but i don't want heat being generated in a box that's packed in 75 or 80 degree temps and sitting at those temps for at least several hours.

So I'm curious to know if anyone's determined the "heat gain" curve over time with heat packs. If no one responds, i'll try to run some tests myself.

Or has anyone ever packed max-min thermometers with their shipments to determine what's experienced en route? the analog ones I've seen would shake and lose their readings. Can anyone recommend a good digital device for that purpose?

thanks
terry
albino tricolors

I have always wondered these myself.

From what I know. Heat packs do not reach there maximum potential until about half way thru its life span (IE. A 20 hour heat pack does not reach full potential until 6-10 hours have gone by.) A 20 hour heat pack gets hot in about 1 hour, a 40 hour heat pack waits almost 2.5 hours, and a 60 hour heat pack takes until about 3-4 hours. When shipping at this time of the year to any norther climate, I recommend only using a 40 hour heat pack unless you are exporting and it might need a 60 hour heat pack. As for 20 hour heat pacs ( I DO NOT USE THEM) I personally think they suck, and ware out way to quick. If there was a delay your package would be frozen. Now as for shipping from a hot climate. I would not worry to much if I was you. As most of the time the box has the potential to stay at room temps and not overheat. This is because UPS and other carriers keep them indoors until loading the plane up. Once on the plane, they will only have a few hours in hot climate before making it into VERY cold weather. I think the styro lining should conserve the temps in the box enough not to worry about overheating. If it did rise to say 90 degrees in the box and then was exposed to cold temps in the 40's, and in even more northern climates the low teens or below zero temps, they will chill very fast. Only relying on the heat packs for heat, so the raise in temp in the box could have helped slow down the cooling process and in affect help to save the animals life. This is just my advice and thought on the matter.
Thanks, Jim

Our reptile rescue is one of a select few that will ship our adopted reptiles. Of course as a rescue we're called to an even higher degree of ethics so we are very strict about adhering to the standards of the industry when it comes to shipping reptiles(not shipping in extreme temps, always 30 or 40 hour heat packs/insulated packaging, etc).

We have never had a problem with a single shipment, but then I consider myself more careful than many live animal shippers would be. If anyone does any studies or experiments on shipping live reptiles, I'd love to read about it, so please let me know.
-----
Jesse Rothacker
Forgotten Friend Reptile Sanctuary
Find out how YOU can get involved in reptile rescue...
www.forgottenfriend.org

Since I am one to want "facts", I did my own test case. Here is what I found.

Used 1" thick Styrofoam in a 15"x11"x7" box, 2 - 40 hour heat packs (one positioned on bottom of box and one positioned on the side), temp probe positioned inside the deli cup where the reptile would be, packed with newspaper (as if I was packing a critter).

Kept the box at room temp, sealed for 3 hours - Temp stabilized at 86 degrees
Moved the box to the frig and kept it there for 6 hours - Temp stabilized at 52 degrees
Moved the box to the freezer and kept it there for 6 hours (freezer temp was 25 degrees)- Temp stabilized at 31 degrees. Brrrrrrrrr.

This is the point I decided I would not ship an animal if the "lows" were below 40 degrees. I am pretty conservative (not a dare devil)...

I have a better insulated box now but have not run the same test results on this box merely due to space in freezer. I purchased a pallet of shipping boxes from www.coldice.com. They are pre-formed insulated boxes, much better quality than the shipping boxes I get from Superior. But even so, I am refraining from shipping critters in below 40 temps.

If anyone else has done a similar test, I would also like to know the findings.

Lori