HowtoBeattheHeat

Endothermsandectothermshavevariouswaystokeepfromgettingtoohot.Onewayissweating.Someendothermssweattokeeptheirbodiesfrom overheating.


Tosweat,nervessendmessagestoyourbrainthatyouareheatingup.Thebrainthensendsmessagestosweatglandstoproducesweat,whichismostlywater.Whenyousweat,heatmovesoutsideyourbodyaswater.Asthewaterevaporates,youcool down.

Dogsdon'tsweat.
Instead,theypanttocool down.

Mostendothermsdon’thavesweatglands.Yet,theyhaveotherwaystocooldown.Dogspant.Witheachbreath,moistureevaporatesfromtheir tongues.


Manyanimalsusetheirearstobeattheheat.Anelephant’slargeearshavemanyveins.Heatfromthewarmbloodworksitswaythroughthethinskinthereandintotheair. Thecooledbloodthencirculatesthroughthe body.

Thiskangaroolicksitsarmtokeep cool.

Thisfennecfoxusesitsbigearstocool down.

Kangarooslicktheirforearmstocooldown.Astheirspitevaporates,thebloodflowingclosetotheskincools.It’sgross,butitworksfor kangaroos.


Manystayoutofthehotsun,evenectotherms.Somelizards,forexample,burrowintothegroundtokeep cool.

Thisiguanaburrowsintothesoiltocool down. 

HowtoTurnUptheHeat

Ectothermssuchasreptilesandamphibianssometimesburrowintothegroundforanotherreason.Whentheweatherturnscold,theyhibernate.Sodosomeinsects,likeladybugs.Otherinsects,likemonarchbutterflies,flytowarmer climates.

Thiswalrus’slayersofblubberhelpprotectitfromthe cold.  

Manyendothermshaveanotherwaytoturnuptheheat.Theyshiver.Thebrainsignalsmusclestovibrate.Thisproducesheattowarmthebody.Mammalsandbirdsshiver.Someectotherms,suchasbees,shiver, too.


Manyendothermshavebodycoveringsthatkeepthemwarm.Hair,fur,orfeatherskeepthecoldairoutandthebodyheatin.Andmarinemammalsgrowthicklayersoffatcalled blubber.

Endothermvs. Ectotherm

So,whichanimalshavetheadvantagetosurvive?Ifasnakewastryingtocatchamouseonacoolday,themouseprobablyhasthe advantage.


Ontheotherhand,thesnakeneedsalotlessfoodthanthemousedoes.Themousehastoeateverydayinordertomaintainitsbodyheat. EndothermscanlivealmostanyplaceonEarth.Mostectothermscanonlysurviveinwarmandmild climates.


It’shardtosaywhichhastheupperhand.Lookslikebothectothermsandendothermshavewaystosurviveintheir environment. 

Amouseisanendotherm.Asnakeisan ectotherm.