HowtoBeattheHeat
Endothermsandectothermshavevariouswaystokeepfromgettingtoohot.Onewayissweating.Someendothermssweattokeeptheirbodiesfrom overheating.
Tosweat,nervessendmessagestoyourbrainthatyouareheatingup.Thebrainthensendsmessagestosweatglandstoproducesweat,whichismostlywater.Whenyousweat,heatmovesoutsideyourbodyaswater.Asthewaterevaporates,youcool down.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414766/dog.640_0_1.jpg)
Dogsdon'tsweat.
Instead,theypanttocool down.
Mostendothermsdon’thavesweatglands.Yet,theyhaveotherwaystocooldown.Dogspant.Witheachbreath,moistureevaporatesfromtheir tongues.
Manyanimalsusetheirearstobeattheheat.Anelephant’slargeearshavemanyveins.Heatfromthewarmbloodworksitswaythroughthethinskinthereandintotheair. Thecooledbloodthencirculatesthroughthe body.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414768/kangaroo.480_0_1.jpg)
Thiskangaroolicksitsarmtokeep cool.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414767/NGX0919_EE_8a.480_0_1.jpg)
Thisfennecfoxusesitsbigearstocool down.
Kangarooslicktheirforearmstocooldown.Astheirspitevaporates,thebloodflowingclosetotheskincools.It’sgross,butitworksfor kangaroos.
Manystayoutofthehotsun,evenectotherms.Somelizards,forexample,burrowintothegroundtokeep cool.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414769/leguaan.1024_0_1.jpg)
Thisiguanaburrowsintothesoiltocool down.
HowtoTurnUptheHeat
Ectothermssuchasreptilesandamphibianssometimesburrowintothegroundforanotherreason.Whentheweatherturnscold,theyhibernate.Sodosomeinsects,likeladybugs.Otherinsects,likemonarchbutterflies,flytowarmer climates.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414770/wallrus.480_0_1.jpg)
Thiswalrus’slayersofblubberhelpprotectitfromthe cold.
Manyendothermshaveanotherwaytoturnuptheheat.Theyshiver.Thebrainsignalsmusclestovibrate.Thisproducesheattowarmthebody.Mammalsandbirdsshiver.Someectotherms,suchasbees,shiver, too.
Manyendothermshavebodycoveringsthatkeepthemwarm.Hair,fur,orfeatherskeepthecoldairoutandthebodyheatin.Andmarinemammalsgrowthicklayersoffatcalled blubber.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414773/NGX0919_EE_9a.240_0_1.png)
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414774/NGX0919_EE_9d.960_0_1.png)
Endothermvs. Ectotherm
So,whichanimalshavetheadvantagetosurvive?Ifasnakewastryingtocatchamouseonacoolday,themouseprobablyhasthe advantage.
Ontheotherhand,thesnakeneedsalotlessfoodthanthemousedoes.Themousehastoeateverydayinordertomaintainitsbodyheat. EndothermscanlivealmostanyplaceonEarth.Mostectothermscanonlysurviveinwarmandmild climates.
It’shardtosaywhichhastheupperhand.Lookslikebothectothermsandendothermshavewaystosurviveintheir environment.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/414772/mouse_heat.480_0_1.jpg)
Amouseisanendotherm.Asnakeisan ectotherm.
![](/nationalgeographic/pathfinder_september_2019/keep_it_steady_and_beat_the_heat_and_turn_up_the_heat_and_endotherm_vs_endotherm/980089/cloudinary_2_jane_20goodall_20id_20chimps.960_0_1.jpg)