diff --git a/dom/ipc/ContentChild.cpp b/dom/ipc/ContentChild.cpp
index cbbd8ef9fbe0..111af7153167 100644
--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -43,6 +43,7 @@
 #if defined(XP_WIN)
 #define TARGET_SANDBOX_EXPORTS
 #include "mozilla/sandboxTarget.h"
+#include "nsDirectoryServiceDefs.h"
 #elif defined(XP_LINUX)
 #include "mozilla/Sandbox.h"
 #endif
@@ -923,6 +924,69 @@ ContentChild::AllocPBackgroundChild(Transport* aTransport,
     return BackgroundChild::Alloc(aTransport, aOtherProcess);
 }
 
+#if defined(XP_WIN) && defined(MOZ_CONTENT_SANDBOX)
+static void
+SetUpSandboxEnvironment()
+{
+    // Set up a low integrity temp directory. This only makes sense if the
+    // delayed integrity level for the content process is INTEGRITY_LEVEL_LOW.
+    nsresult rv;
+    nsCOMPtr<nsIProperties> directoryService =
+        do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return;
+    }
+
+    nsCOMPtr<nsIFile> lowIntegrityTemp;
+    rv = directoryService->Get(NS_WIN_LOW_INTEGRITY_TEMP, NS_GET_IID(nsIFile),
+                               getter_AddRefs(lowIntegrityTemp));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return;
+    }
+
+    // Undefine returns a failure if the property is not already set.
+    unused << directoryService->Undefine(NS_OS_TEMP_DIR);
+    rv = directoryService->Set(NS_OS_TEMP_DIR, lowIntegrityTemp);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return;
+    }
+
+    // Set TEMP and TMP environment variables.
+    nsAutoString lowIntegrityTempPath;
+    rv = lowIntegrityTemp->GetPath(lowIntegrityTempPath);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return;
+    }
+
+    bool setOK = SetEnvironmentVariableW(L"TEMP", lowIntegrityTempPath.get());
+    NS_WARN_IF_FALSE(setOK, "Failed to set TEMP to low integrity temp path");
+    setOK = SetEnvironmentVariableW(L"TMP", lowIntegrityTempPath.get());
+    NS_WARN_IF_FALSE(setOK, "Failed to set TMP to low integrity temp path");
+}
+
+void
+ContentChild::CleanUpSandboxEnvironment()
+{
+    nsresult rv;
+    nsCOMPtr<nsIProperties> directoryService =
+        do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return;
+    }
+
+    nsCOMPtr<nsIFile> lowIntegrityTemp;
+    rv = directoryService->Get(NS_WIN_LOW_INTEGRITY_TEMP, NS_GET_IID(nsIFile),
+                               getter_AddRefs(lowIntegrityTemp));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return;
+    }
+
+    // Don't check the return value as the directory will only have been created
+    // if it has been used.
+    unused << lowIntegrityTemp->Remove(/* aRecursive */ true);
+}
+#endif
+
 bool
 ContentChild::RecvSetProcessSandbox()
 {
@@ -947,6 +1011,7 @@ ContentChild::RecvSetProcessSandbox()
     if (contentSandboxPref.EqualsLiteral("on")
         || contentSandboxPref.EqualsLiteral("warn")) {
         mozilla::SandboxTarget::Instance()->StartSandbox();
+        SetUpSandboxEnvironment();
     }
 #endif
 #endif
diff --git a/dom/ipc/ContentChild.h b/dom/ipc/ContentChild.h
index 6f529e7a4a80..c85ff9ab0794 100644
--- a/dom/ipc/ContentChild.h
+++ b/dom/ipc/ContentChild.h
@@ -118,6 +118,11 @@ public:
     AllocPImageBridgeChild(mozilla::ipc::Transport* aTransport,
                            base::ProcessId aOtherProcess) MOZ_OVERRIDE;
 
+#if defined(XP_WIN) && defined(MOZ_CONTENT_SANDBOX)
+    // Cleans up any resources used by the process when sandboxed.
+    void CleanUpSandboxEnvironment();
+#endif
+
     virtual bool RecvSetProcessSandbox() MOZ_OVERRIDE;
 
     PBackgroundChild*
diff --git a/dom/ipc/ContentProcess.cpp b/dom/ipc/ContentProcess.cpp
index bf8e190e63d1..c3037fcd1f53 100644
--- a/dom/ipc/ContentProcess.cpp
+++ b/dom/ipc/ContentProcess.cpp
@@ -34,6 +34,9 @@ ContentProcess::Init()
 void
 ContentProcess::CleanUp()
 {
+#if defined(XP_WIN) && defined(MOZ_CONTENT_SANDBOX)
+    mContent.CleanUpSandboxEnvironment();
+#endif
     mXREEmbed.Stop();
 }
 
diff --git a/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp b/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp
index 39ee19b9e3a6..f1c2d1843fcd 100644
--- a/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp
+++ b/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp
@@ -73,13 +73,16 @@ SandboxBroker::SetSecurityLevelForContentProcess(bool inWarnOnlyMode)
 
   auto result = mPolicy->SetJobLevel(sandbox::JOB_NONE, 0);
   bool ret = (sandbox::SBOX_ALL_OK == result);
-  result =
-    mPolicy->SetTokenLevel(sandbox::USER_RESTRICTED_SAME_ACCESS,
-                           sandbox::USER_RESTRICTED_SAME_ACCESS);
+
+  result = mPolicy->SetTokenLevel(sandbox::USER_RESTRICTED_SAME_ACCESS,
+                                  sandbox::USER_RESTRICTED_SAME_ACCESS);
   ret = ret && (sandbox::SBOX_ALL_OK == result);
-  result =
-    mPolicy->SetDelayedIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
+
+  // If the delayed integrity level is changed then SetUpSandboxEnvironment and
+  // CleanUpSandboxEnvironment in ContentChild should be changed or removed.
+  result = mPolicy->SetDelayedIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
   ret = ret && (sandbox::SBOX_ALL_OK == result);
+
   result = mPolicy->SetAlternateDesktop(true);
   ret = ret && (sandbox::SBOX_ALL_OK == result);
 
diff --git a/xpcom/io/SpecialSystemDirectory.cpp b/xpcom/io/SpecialSystemDirectory.cpp
index 939032f310ad..8bad192d9647 100644
--- a/xpcom/io/SpecialSystemDirectory.cpp
+++ b/xpcom/io/SpecialSystemDirectory.cpp
@@ -751,6 +751,14 @@ GetSpecialSystemDirectory(SystemDirectories aSystemSystemDirectory,
       }
       return rv;
     }
+#if defined(MOZ_CONTENT_SANDBOX)
+    case Win_LocalAppdataLow: {
+      // This should only really fail on versions pre-Vista, in which case this
+      // shouldn't have been used in the first place.
+      GUID localAppDataLowGuid = FOLDERID_LocalAppDataLow;
+      return GetKnownFolder(&localAppDataLowGuid, aFile);
+    }
+#endif
     case Win_Documents: {
       return GetLibrarySaveToPath(CSIDL_MYDOCUMENTS,
                                   FOLDERID_DocumentsLibrary,
diff --git a/xpcom/io/SpecialSystemDirectory.h b/xpcom/io/SpecialSystemDirectory.h
index 9142f2278ee1..dd3d88379580 100644
--- a/xpcom/io/SpecialSystemDirectory.h
+++ b/xpcom/io/SpecialSystemDirectory.h
@@ -79,6 +79,9 @@ enum SystemDirectories {
   Win_Pictures              =   233,
   Win_Music                 =   234,
   Win_Videos                =   235,
+#if defined(MOZ_CONTENT_SANDBOX)
+  Win_LocalAppdataLow       =   236,
+#endif
 
   Unix_LocalDirectory       =   301,
   Unix_LibDirectory         =   302,
diff --git a/xpcom/io/nsDirectoryService.cpp b/xpcom/io/nsDirectoryService.cpp
index c1e231d51df5..a7c3d3222602 100644
--- a/xpcom/io/nsDirectoryService.cpp
+++ b/xpcom/io/nsDirectoryService.cpp
@@ -24,6 +24,10 @@
 #include <shlobj.h>
 #include <stdlib.h>
 #include <stdio.h>
+
+#if defined(MOZ_CONTENT_SANDBOX)
+#include "nsIUUIDGenerator.h"
+#endif
 #elif defined(XP_UNIX)
 #include <unistd.h>
 #include <stdlib.h>
@@ -499,6 +503,47 @@ nsDirectoryService::UnregisterProvider(nsIDirectoryServiceProvider* aProv)
   return NS_OK;
 }
 
+#if defined(MOZ_CONTENT_SANDBOX) && defined(XP_WIN)
+static nsresult
+GetLowIntegrityTemp(nsIFile** aLowIntegrityTemp)
+{
+  nsCOMPtr<nsIFile> localFile;
+  nsresult rv = GetSpecialSystemDirectory(Win_LocalAppdataLow,
+                                          getter_AddRefs(localFile));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIUUIDGenerator> uuidgen =
+    do_GetService("@mozilla.org/uuid-generator;1", &rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsID uuid;
+  rv = uuidgen->GenerateUUIDInPlace(&uuid);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  char uuidChars[NSID_LENGTH];
+  uuid.ToProvidedString(uuidChars);
+  rv = localFile->AppendNative(NS_LITERAL_CSTRING(MOZ_USER_DIR));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = localFile->AppendNative(NS_LITERAL_CSTRING("MozTemp-")
+                               + nsDependentCString(uuidChars));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  localFile.forget(aLowIntegrityTemp);
+  return rv;
+}
+#endif
+
 // DO NOT ADD ANY LOCATIONS TO THIS FUNCTION UNTIL YOU TALK TO: dougt@netscape.com.
 // This is meant to be a place of xpcom or system specific file locations, not
 // application specific locations.  If you need the later, register a callback for
@@ -671,6 +716,12 @@ nsDirectoryService::GetFile(const char* aProp, bool* aPersistent,
     rv = GetSpecialSystemDirectory(Win_Appdata, getter_AddRefs(localFile));
   } else if (inAtom == nsDirectoryService::sLocalAppdata) {
     rv = GetSpecialSystemDirectory(Win_LocalAppdata, getter_AddRefs(localFile));
+#if defined(MOZ_CONTENT_SANDBOX)
+  } else if (inAtom == nsDirectoryService::sLocalAppdataLow) {
+    rv = GetSpecialSystemDirectory(Win_LocalAppdataLow, getter_AddRefs(localFile));
+  } else if (inAtom == nsDirectoryService::sLowIntegrityTemp) {
+    rv = GetLowIntegrityTemp(getter_AddRefs(localFile));
+#endif
   } else if (inAtom == nsDirectoryService::sPrinthood) {
     rv = GetSpecialSystemDirectory(Win_Printhood, getter_AddRefs(localFile));
   } else if (inAtom == nsDirectoryService::sWinCookiesDirectory) {
diff --git a/xpcom/io/nsDirectoryServiceAtomList.h b/xpcom/io/nsDirectoryServiceAtomList.h
index b6bf658631ab..d61446a525c2 100644
--- a/xpcom/io/nsDirectoryServiceAtomList.h
+++ b/xpcom/io/nsDirectoryServiceAtomList.h
@@ -71,6 +71,10 @@ DIR_ATOM(sCommon_Desktopdirectory, NS_WIN_COMMON_DESKTOP_DIRECTORY)
 DIR_ATOM(sCommon_AppData, NS_WIN_COMMON_APPDATA_DIR)
 DIR_ATOM(sAppdata, NS_WIN_APPDATA_DIR)
 DIR_ATOM(sLocalAppdata, NS_WIN_LOCAL_APPDATA_DIR)
+#if defined(MOZ_CONTENT_SANDBOX)
+DIR_ATOM(sLocalAppdataLow, NS_WIN_LOCAL_APPDATA_LOW_DIR)
+DIR_ATOM(sLowIntegrityTemp, NS_WIN_LOW_INTEGRITY_TEMP)
+#endif
 DIR_ATOM(sPrinthood, NS_WIN_PRINTHOOD)
 DIR_ATOM(sWinCookiesDirectory, NS_WIN_COOKIES_DIR)
 DIR_ATOM(sDefaultDownloadDirectory, NS_WIN_DEFAULT_DOWNLOAD_DIR)
diff --git a/xpcom/io/nsDirectoryServiceDefs.h b/xpcom/io/nsDirectoryServiceDefs.h
index 0c4a474f08f3..d0e3df51e344 100644
--- a/xpcom/io/nsDirectoryServiceDefs.h
+++ b/xpcom/io/nsDirectoryServiceDefs.h
@@ -120,6 +120,10 @@
   #define NS_WIN_COMMON_APPDATA_DIR           "CmAppData"
   #define NS_WIN_APPDATA_DIR                  "AppData"
   #define NS_WIN_LOCAL_APPDATA_DIR            "LocalAppData"
+#if defined(MOZ_CONTENT_SANDBOX)
+  #define NS_WIN_LOCAL_APPDATA_LOW_DIR        "LocalAppDataLow"
+  #define NS_WIN_LOW_INTEGRITY_TEMP           "LowTmpD"
+#endif
   #define NS_WIN_PRINTHOOD                    "PrntHd"
   #define NS_WIN_COOKIES_DIR                  "CookD"
   #define NS_WIN_DEFAULT_DOWNLOAD_DIR         "DfltDwnld"